In the mid 1970s, the world of motorsport seemed to be on its last legs. As the entire Western world gasped for air in the wake of the devastating oil shortages caused by the 1973 Yom Kippur War, a frivolous and inherently expensive activity such as motor racing almost seemed like a thing of the past.

Due to the sharp economic downturn and a new emphasis on fuel efficiency, races were shortened or even outright cancelled, and even entire championships collapsed. Faced with completely reworking their model range to reflect the changing times, most manufacturers cut the budget for what were suddenly very negative and needlessly expensive activities. As a result, many a racing department was put in suspended animation.

A typical scene in 1973. A typical scene in 1973.

With not even the biggest brand in the business being immune to the effects of the energy crisis, the Automobile Club de l'Oest was forced to spring into action. The ACO was the principal governing body of the most famous endurance race on the planet, the 24 Hours of Le Mans. Though the Federation Internationale de l'Automobile traditionally determined the technical requirements and overall class structure, the ACO retained a certain degree of freedom.

Using this liberty, the Club moved to introduce a series of countermeasures to the dramatically dwindling grids. One of these initiatives was to approach American IMSA and even NASCAR teams to come over and have a go in the French countryside, the other was the allowance of Group 2 touring cars and Group 3, Group 4 and Group 5 GT cars.

Even little touring cars like this BMW 2002 Ti were invited to help bolster the grids. Even little touring cars like this BMW 2002 Ti were invited to help bolster the grids.

Additionally, the ACO created the Grand Touring Experimental class. This was intended for cars which hadn't yet reached homologation in one of the FIA Groups, and as a result were free to use non-homologated parts. GTX was really a last ditch attempt to give any and every racing team with a random sportscar sitting out front a chance to race at Le Mans, as the ACO was terrified of the prospect of the pits turning into a ghost town.

The drastic loosening of entry standards wasn't just motivated by the perceived threat of the energy crisis. In fact, the organization had announced a very unpopular measure to deal with the issue head-on. For the 1975 race, all teams were required to run at least 20 laps on a 100L fuel tank, giving rise to the jeering moniker "Le Mans Economy Run".

The ungainly looking Islero would be the first Lamborghini to engage in racing. The ungainly looking Islero would be the first Lamborghini to engage in racing.

The change didn't sit well with both the works teams of Alfa Romeo, Alpine-Renault and Ferrari, which all promptly left the sport or simply declined to compete, citing the impossible fuel consumption demands.

For example, the winning Matra MS670C had only managed 16 laps on a full tank in 1974, and that was with unrestricted tank size. As Matra had also left the sport at the end of that season, only Gulf-Mirage and Ligier were left to pick up the pieces.

The Commission Sportive Internationale of the FIA was similarly miffed, and consequently punished the ACO by removing Le Mans' World Championship status. The break between the two governing bodies had the added side-effect of postponing the introduction of the new Group 5 silhouette racers to 1976.

Despite the strict fuel economy regimen upheld by the ACO, the tactic seemed to work. As much as 101 applications were received for the race, which was whittled down to 71 for qualifying, and 55 for the actual race.

One of these entrants was French auto merchant Paul Rilly. Together with his friend Roger Leveve, Rilly dreamed of racing a car at Circuit de La Sarthe. With the incredibly lax GTX regulations, he finally had a chance to do so.

As luck would have it, Paul had a perfectly good Ferrari sitting around his yard. Unfortunately, his exuberance took its toll one day, as he managed to blow the car's engine three months before the start of the race. As a quick backup, he entered a Porsche 911 3.0 RSR instead.

However, the Porsche quickly lost his interest. Just six months before, Rilly had bought a silver 1968 Lamborghini Islero from Garage Europ Sport near the track of Monthlery, Paris.

The Islero was a quirky 2+2 front-engined GT, powered by a creamy 3.9L V12. He had been driving it around as his personal car, repainted in a striking shade of orange borrowed from the paint catalog of the contemporary BMW 2002.

Paul Rilly traveled to the Lamborghini factory to explain his plans. Paul Rilly traveled to the Lamborghini factory to explain his plans.

Unbeknownst to Paul, the car, chassis # 6009, was actually one of the very first Isleros to roll out of the factory. Essentially a pre-production example, the light green machine was given to French Sport Auto journalist and amateur racing driver Jose Rosinski for a road test.

Rosinski complained of poor braking performance, causing Edmond Ciclet, chief mechanic of French Lamborghini importer Garage Thepanier, to take it out for a test drive. Ciclet then promptly proved Rosinski's point by wrecking the car in a high speed crash.

Three weeks later the rebuilt Islero was shining away on the floor of the 1968 Paris Motor Show, after which it was sold to an undisclosed party. In October of 1971, the car changed hands and was repainted silver. Three years later, it graced the showroom of Garage Europ Sport, when Rilly walked in.

Paul Rilly (left) and Roger Leveve, Paul Rilly (left) and Roger Leveve,

After considering the overabundance of Porsche entries at Le Mans, Paul Rilly decided it would be much better to pit the big Lambo against them to grab headlines. However, the Islero would need a lot more preparation than the race-ready 911, and competition parts weren't actually available.

In an effort to get some professional help with the project, he contacted Garage Thepanier. Through contacts there, he was granted audience with Ferruccio Lamborghini's right-hand man Ubaldo Sgarzi at the Sant'Agata Bolognese factory.

At first glance, the Islero appeared to offer little in the way of racing spirit. At first glance, the Islero appeared to offer little in the way of racing spirit.

Over at the factory, Paul Rilly tried to convince Sgarzi to break his boss's one rule. From the very beginning, Ferruccio Lamborghini had vowed never to be distracted by the world of motorsport, as his cars would be the ultimate for the road. Rilly's efforts proved to be futile, as Ubaldo remained loyal to the company doctrine.

However, the Italian was still sympathetic to Paul's plight, and offered to supply an uprated suspension and brake kit to improve the Islero's performance. After an amount of 15.000 Francs had been paid, Paul Rilly was on his way back to France to attempt the impossible.

Back home, the specialized parts were fitted to the Islero, which received a much-needed engine overhaul as well. As he had neither the means nor the funds to alter anything else, the the bare minimum was done for the Lamborghini to adhere to the ACO's safety standards.

This meant the addition of a full roll cage, a racing safety harness, a 100 liter fuel cell, quick-release bonnet locks, and a small light on the side illuminating the start number. With no significant changes to the engine, power was still around the standard 315 horsepower.

The car's five-speed manual transmission was retained as well, and given 377 Nm (278 lb ft) to deal with. With only minor weight reduction, the car was actually heavier than the stock 1380 kg (3042 lbs), as the safety equipment brought weight up to 1443 kg (3181 lbs).

The car wasn't really modified on a technical level. The car wasn't really modified on a technical level.

Just two weeks before the start of the race, Paul Rilly finally filed the application for his unique car. Probably helped by its unusual name, his entry was accepted for qualification, bringing Rilly one step closer to an actual start.

Together with Roger Leveve, Paul Rilly faced the prospect of dealing with nearly fourteen kilometers of untamed roads. With the traditional test weekend cancelled due to a slightly deliberate scheduling conflict with FIA World Championship race at Mugello, the team had very little time to adapt to any issues they would encounter during the practice.

Naturally, they encountered trouble almost right away. During hard braking at the end of the seemingly endless Hunaudieres straight, the Islero was operating much like a flyswatter.

In response to this nervous behavior, Edmond Ciclet redesigned the cooling ducts towards the rear brakes. While he was at it, the carburetors were fettled with as well, in hopes of increasing the car's rather lackluster top speed.

The comical stubby exhausts turned out to be a misguided addition tot the big Lambo. The comical stubby exhausts turned out to be a misguided addition tot the big Lambo.

Seeking even more top speed, Paul Rilly managed to secure a set of big bore, short exhausts from a Capri RS3100, which he promptly fitted to the big V12. Though his intentions were good, he really didn't think it through, as he failed to adjust the rest of the car to the blaring sidepipes.

The gung-ho modification turned out to have an adverse effect on the Islero, as it actually slowed it down. Edmond Ciclet had already left the track for other important business, but Paul Rilly was able to get a hold of him through the phone. Ciclet then gave him instructions on how to adjust the V12's carbs, enriching the mixture to take advantage of the larger exhaust pipes.

Rilly never got the car to work properly. Rilly never got the car to work properly.

Though this adjustment seemed to work, giving a new top speed of 265 kph (164 mph). However, it also presented a new issue. Thanks to the lower ride height caused by the sports suspension and smaller circumference racing tires, the side pipes were now dragging along the road in tight corners due to the car's body roll. This made the team lose time in the pits once again, to Paul Rilly's frustration.

In an effort to improve the ever growing gap between the Lamborghini and the rest of the field, Rilly gave the car to an unnamed Formula 2 driver. Sadly, even this man wasn't able to improve the car's weak lap time, pitching it into the guardrail instead.

With a best lap time of just 5:28.00, the car was a demoralizing 47.1 seconds behind the last qualifier, the Ecuador Team Marlboro Porsche 911 Carrera 3.0 RSR of Fausto Merello and Guillermo Ortega.

With that final time posted, Paul Rilly drew his conclusions. As his mechanics worked to put the car back together, he dejectedly left for home. As he was on the road, his pitbox received some completely unexpected news. They would be allowed to start after all.

As it happened, North American Racing Team's Luigi Chinetti had been engaged in a battle with the ACO over his semi-works Ferrari 308 GT4/LM, which he had intended as a Group 4 GT car. However, during scrutineering the car was reclassified by the stewards as a S3.0 prototype, citing too many deviations from the standard model, and a lack of proper homologation.

The NART Ferrari 308 GT4/LM caused a war between Luigi Chinetti and the ACO. The NART Ferrari 308 GT4/LM caused a war between Luigi Chinetti and the ACO.

In retaliation for their refusal to allow his car to start as a GT, Chinetti pulled out all four of his cars, a GTS-class Ferrari 365 GTB/4 Daytona Competizione, a unique Spyder variant, a GTX-class 365 Berlinetta Boxer and the GT4.

The sudden vacancies opened up four spots for cars which hadn't actually qualified. Even though the Islero was one of the slowest cars around, it was still selected for its exotic looks. As the officials brought the news to Rilly's crew, the men were both delighted and shocked. They needed to contact him immediately.

With cellphones and even car phones still in the realms of science fiction, the men had no other option than to contact Rilly's home address. Sadly, Paul wasn't able to answer the phone until Saturday morning, just after the warm up had finished.

With no time to bring him back for the start, the ACO decided to replace the Lamborghini with another entry. Stunned, Paul Rilly was left to sit on his couch and stare into space, wondering about what might have been.

After the horrors of Le Mans, Paul Rilly retained the Islero in full race spec, and kept using it as his personal car. During this time, the car still sported the plates of its previous owner. Rilly blasted around town in the immensely loud Lamborghini, until he was inevitably awarded a hefty fine by the local police.

The reprimand prompted him to finally register the car to his name, before selling it back to Garage Europ Sport in 1977. A young Parisian then became the new owner, curiously keeping Rilly's license plate. Around two years later, he too sold the car back to Europ Sport, upon which it faded into obscurity.

The Islero remained missing until 2008, when Belgian Lamborghini club president Olivier Nameche finally tracked it down to a barn in Clermont-Ferrand. Nameche rescued the car for restoration, after which it was sold to an unnamed Frenchman. And so, the story of the first ever Lamborghini to take part in a race weekend, and the first to appear at Le Mans, finally ended on a positive note.