Many drivers would be content - if not thrilled - to own a high-performance European car. Though Ferrari, Lamborghini, Porsche and Mercedes-AMG make some of the wildest cars in the world, a handful of wealthy enthusiasts think they aren't quite wild enough. Meet the tuners rubbing shoulders with manufacturers at the Geneva motor show.

Brabus - Mercedes-AMG S65 Coupe

The Mercedes-AMG S65 Coupe has one of the world's most powerful engines, a 6.0-liter twin-turbocharged V12 that makes 463kW and 1000Nm in standard trim. Power-crazed enthusiasts looking to improve on that can order the Brabus Rocket 900, a S65-based coupe that offers 662kW and 1500Nm thanks to supersized turbos and a step up to 6.3 litres of engine capacity.

The result is an executive jet that can rip to 100km/h in 3.7 seconds, on to a top speed well in excess of 350km/h.

If that's too wild, the company also offers a smaller model based on the new Mercedes-AMG C63 S that gives the brand's most popular sedan a phenomenal 478kW of power and 820Nm of torque.

Hamann - BMW X6M

Though it may look like a BMW X6 with a simple body kit and oversized 23-inch wheels, there is much moire to Hamann's "Tycoon" than meets the eye. A significant upgrade to the SUV's motor lifts power to a claimed 500kW and 1000Nm - suspiciously neat figures - that should help it outgun plenty of Supercars on the road.

Some of Europe's best tuning houses put on a show at Geneva. Photo: Supplied

Ruf - Porsche 911

Porsche returned to its roots at Geneva with the retro 911 R, a car that built on its track-developed 911 GT3 coupe. Ruf takes that a step further by offering a car Porsche won't - a turbocharged successor, in spirit at least, to the heavy-hitting 911 GT2. Powered by a twin-turbocharged 3.8-litre engine, Ruf's Porsche-based RTR sends 598kW of power to the rear wheels via a six-speed manual transmission - enough to reach a top speed of 350km/h.

Alpina - BMW 7-Series

Meet the hot BMW that could be coming to a dealership near you. Alpina, a brand with immense history in Europe, has turned its attention to the latest BMW 7-Series. Transforming the limousine into a serious Muscle car, Alpina worked the BMW's 4.4-litre V8 to the tune of 447kW and 800Nm, enough for the full-sized sedan to streak well beyond 300km/h. BMW Australia says it is considering whether to offer Alpina products through local dealerships, which would give local customers an alternative to the brand's highly-regarded M performance cars.

Kahn - Aston Martin DB9

Looking to stand out in a neighborhood drowning in Aston Martins? Kahn has the car for you. Meet the Vengeance, a reworked DB9 that follows the likes of Zagato by offering new coach work for the British brand's finest coupes.

The Kahn retains Aston Martin's signature V12 engine, which benefits from extra traction thanks to fat 335mm-wide rear types.

Some of Europe's best tuning houses put on a show at Geneva. Photo: Supplied

Fab Design - Mercedes-AMG GT

While Mercedes-AMG has confirmed plans to build hotter versions of it's new AMG GT Coupe, it's unlikely they will be this spicy.

Meet the Fab Design Areion, a car that combines muscular looks with serious power - 522kW and 1025Nm - thanks to new turbochargers and a more efficient exhaust.

Customers can have Fab Design's bodywork painted to match their car or leave the raw carbon fibre exposed, lending a race-ready appearance.

Mansory - Ferrari 488 GTB

It takes a bold customer to toss away the lovingly created panels of a Ferrari 488 GTB or Mercedes-AMG GT before replacing it with the outlandish bodywork offered by Mansory.

Subtlety is in short supply; it's a little like asking a waiter for pepper and waiting for the grinder to exhaust it's supply before saying "when".

The Mansory 4XX Siracusa borrows styling touches from Ferrari's FXXK track car, lending additional aerodynamic effects as well as an extra dollop of power that lifts the car's output to 590kW.

A similar treatment for the Mercedes-AMG GT results in a car half a metre wider than the original vehicle, along with performance to match.

MTM - Audi RS3

The giant-killing reputation enjoyed by Audi's RS3 Sportback will not by hurt by MTM's tuning attempts.

The German go-fast crew worked their magic on the hot hatch's five-cylinder engine, boosting power from 270kW to a fairly impressive 370kW and 650Nm. The result is a car that can rip to 100km/h in just 3.6 seconds, thanks to a new exhaust, larger turbocharger and improved intercooler. Speed rarely comes cheap, though, and the MTM Audi is no exception.

European enthusiasts keen on the car need to start with a €53,500 ($79,800) RS3, to which they can add €23,180 ($42,500) in power upgrades. Going all out with a range of performance and cosmetic changes costs €94,316 ($140,500) including the car and installation, which should prevent all but the most committed drivers from getting hold of one.

Nimrod Performance - Lamborghini Aventador

​Hungarian tuners Nimrod Performance turned heads at Geneva with two Ferraris and a Lamborghini. The Aventador-based "Avanti Toto" took pride of place on its stand, featuring daring design cues that make regular Lamborghinis seem restrained.

Nimrod's cosmetic upgrade focuses on the look and feel of Lamborghini's flagship supercar, leaving it's performance alone... Unless you want to tick the option box marked "twin turbo upgrade" and experience earth-shattering performance.

AC Schnitzer - BMW 2-Series

Can't be bothered waiting for an example of BMW's new M2? AC Schnitzer has your answer. The tuning house has managed to stuff an upgraded engine, transmission and suspension from BMW's M4 coupe into the more compact 2-Series body, resulting in a 425kW monster capable of reaching well more than 320km/h.

TechArt - Porsche 911

Porsche specialists TechArt rolled up to Geneva with a relatively restrained series of upgrades for the 911, Cayenne and Panamera. The European concern offers bodywork in lightweight carbon fibre for many key models, along with more aggressive styling for supporters of the German marque. Its engine package for the Cayenne Turbo lends an additional 132kW of power, taking peak torque to 920Nm.