How does a 575bhp, £147,500 Range Rover Sport grab you? Probably with considerably less traction than its all-wheel drive system is renowned for.

Due to be shown for the first time at Salon Privé, 5th to 7th of September at Syon Park, West London, the GTS-X will be joined by its equally outlandish sibling – the £89,995 Evoque 2012 GTS.

Overfinch has modified the donor Range Rover Sport’s 5-litre supercharged V8 engine, adding a new driver-controlled valve release exhaust system, to generate 575bhp, 700Nm of torque and reach a top speed of 145mph. Unsurprisingly the tuner neglects to mention the GTS-X’s resulting fuel economy and C02 emission figures.

Performance and a spectacular soundtrack is one thing, but what about its street-appeal, after all that’s where cars like this will spend most of the time.

The Overfinch GT-X features new sculpted colour-coded side panels, vents with gloss black mouthpiece and new two-tone Overfinch lettering across the bonnet and tailgate. The styling package is finished off with daytime running lights, copper orange paintwork and 22-inch alloy wheels.

Inside the car features carbon-fibre-effect leather with copper orange contrast stitching. Full nappa leather embellishes the special Overfinch seats, headlining, pillars, boot and door cards while an orange-stitched steering wheel completes the high performance look.

In the true Overfinch tradition, the GT-X is quick – reaching 60mph 0.9 seconds faster than the standard supercharged Range Rover Sport, in just 5.0 seconds but thankfully the company has also had the sense to fit 380mm ventilated and drilled Brembo brakes to make sure it can stop just as quickly.

If £147,500 seems a little steep, then perhaps Sir would like an ultra-violet hued Range Rover Evoque 2012 GTS for a snip under £90,000. Complete with Lotus White leather interior, more sculpted styling, 22” diamond turned wheels and an array of bespoke options it’s bound to get you noticed. If that’s really what you want.

They’ll both be on display at the Salon Privé super car lawn next month.