The Lotus Elise is 25 years old next year - a genuine classic come the autumn of 2021 - yet it's still able to educate a modern audience on driver involvement and the efficiency beneflow mass sports car. For a quarter of a century it's been reducing seasoned writers to yabbering wrecks with its delicacy, finesse and poise. Whatever the future holds for Lotus's smallest sports car, the same again in the brave new world of electrification surely wouldn't do it any harm.

But the Elise story was very nearly a mere novella. To be frank, it could well have been the final chapter of a Lotus tale more emotional than Sebastian Faulks' fiction. Not long after the original Elise was introduced, safety legislation was drafted up that would outlaw it come the new millennium. Lotus, being Lotus, simply didn't have the cash at the time to rework and re-homologate the car for the new era; the Elise was going to meet its maker after just four years on sale. And where would the brand be then? Selling an old Esprit for a little while, and going out of business soon after. It's becoming almost tedious to say it nowadays, but the Elise did save Lotus.

And the Vauxhall VX220 saved the Elise. Which is a nice story to tell, almost 20 years since the first VX went on sale, even if more than a few on these pages will be familiar with it. Noticing Lotus's plight, General Motors - sometime owner of Lotus, remember, and with previous in the shape of the Lotus Carlton - stepped in to save the day. A deal was struck that benefitted both Lotus' desire to improve the Elise and Opel's want for sports car - Hethel agreed, and the result is the cars you see here.

It's often overlooked nowadays, but this was a huge deal for Lotus. And for Vauxhall, in fact. The UK was set to be the VX's biggest market, a halo car to sit atop a stolid model line-up, and as such the project was shrouded in secrecy; 'Project Skipton' was a deliberately unsexy name chosen so as not to arouse suspicion.

To accommodate the anticipated production in Norfolk, with plans for 7,000 Opels/Vauxhalls to be sold over three years, £6 million was put into a significant expansion of Hethel to ensure it could cope. Engineers came over from Russelheim to help out with the build; designers had just nine months leading up to the 1999 Geneva show to come up with a concept; and people like Gavan Kershaw had to ensure that the car retained all the good bits of an Elise while giving the Vauxhall its own discernible character. No easy feat.

Yet it all proved worthwhile, at least as far as critical reception went. The VX was a more powerful, more approachable, more accommodating Elise, which could only ever be a good thing. .

So where did they differ? In addition to a 30mm increase in wheelbase and a 20mm-wider rear track, the VX220 also had a slightly softer set up, 17-inch wheels up front instead of the Elise's 16s, and standard ABS. What it lacked in outright agility compared to the Lotus it made up for in (relative) predictability - 'user-friendly' is often a term used to describe it.

The engines were certainly different, too. At launch the S2 Elise was still K-Series powered, revvy and eager in classic sports car fashion. The 220 used a larger, 2.2-litre four-cdespite what many came to believe, the VX's 2,198cc Ecotec wasn't just dumped in from an Astra, either. It had its own inlet and exhaust manifolds, as well as a bespoke air intake so it could be placed in the middle. It was still more about torque than screaming revs, with 90 per cent of its peak available from less than 2,000rpm, and it ensured a different character to the flightier Elise.

Which, however perverse it might sound, is the joy of these two cars, and why the Elise and VX220 are the perfect pair to kick off this series with. Because they were both brilliant, sharing the benefits of aluminium architecture while diverging in key areas to make them feel different as well. So often these exercises between brands result in identical cars with different badges; both Lotus and GM wanted to ensure this didn't happen with the Elise and VX220, and succeeded, with just 10 per cent of parts shared. One gave you the very purest, very lightest, very essence of the mid-engined sports car, while the other still offered absolute exhilaration, albeit in a package that didn't quite require you to be a Hethel test driver to get the very best from it.

The two even evolved along very similar paths. When the S2 Elise was due some extra power, the K Series was taken to its VHPD zenith for the Sport 190. The VX220, on the other hand, opted for the turbo route, with the original, 145hp 2.2 making way in 2003 for the 200hp Turbo cars. These became the biggest sellers in the UK, with supercar-troubling performance and further dynamic tweaks to exploit it best. In fact, at 930kg they were a significant amount more than the 780kg first claimed for a base Elise S2, but the plaudits continued to flood in - the VX now as exciting down the straights as it always has been through bends.

Yet, even at £25k, sales never reached anticipated levels. Early signs for the VX220 were good, with nearly half the first year's allowance sold out before deliveries began. Nevertheless, the planned 1,000 cars a year never materialised, with 450 sold in the first full year on sale and the Speedster/VX duo selling a total of 7,700 units in five years - way behind schedule. Which, given all the effort that was heaped into the car and the praise it received, seems a crying shame. Especially given the thousands of Elises that have been sold, and the love that will be shown for it come anniversary time.

There were problems, though, and they are undeniable. Build quality issues not only ate into profits as VXs were being fixed under warranty, they also did nothing for the image: you expected your Lotus to break down, but not your Vauxhall. And that's assuming you'd be happy to purchase a Vauxhall in the first instance. With both the base Elise and VX220 costing £22,995 at launch, many opted for the romance of a Lotus badge on their mid-engined roadster rather than a more prosaic Griffin. Arguably nothing says more about the fickleness of British buyers and their slavish dedication to brands than the VX's lack of commercial success. Because, 20 years later, nothing more tangible has been established for slow sales of something just as good.

As it transpired, the contract between Lotus and GM had to be torn up because numbers never met expectations, and production of the VX220 ceased in August 2005. The Elise continued, arguably towards its strongest period in fact, as the Toyota-engined cars really came into their own. And the VX220 was left languishing, the Vauxhall sports car had saved the industry's sweetheart largely snubbed by a dismissive British public. Shame.

Still today it makes a canny purchase for the sports car buyer, offering up Lotus genius for a chunk less cash. The VX represents a milestone, too, perhaps the last project of its kind that Vauxhall would embark on. Even then, pre-financial meltdown, six years of non-profitability was brave, and is never going to happen again now on a sports car idea. So let's all be glad it happened at all, and that two excellent vehicles were created from one inspired idea. Because, whether you prefer the VX or the Elise, or a completely different kind of roadster, there's one thing we can all agree on: the more sports cars in the world, the better.

Thanks to Simon Hucknall at Vauxhall for his help with this feature, and the excellent Graham Borrajo on YouTube as well - see his VX220 video here.