When dealing with the amount of money and prestige involved with a custom Bentley Continental, it's easy to get carried away - and there are plenty of examples to attest to that. But sometimes a custom house pulls off an upgrade that actually enhances the original, and that's exactly what we have with the MTM Birkin Edition Bentley Continental GT.

The kit adds 90hp, raising the output to 650hp from the big V12 engine, and lifting torque to 587lb-ft. That's enough grunt to get the big car up to 62mph (100km/h) in just 4.9 seconds and on to 124mph (200km/h) in 15.9 seconds - three seconds quicker than the stock version.

MTM also lays claim to the title of 'world's fastest Bentley' thanks to the Birkin Edition's 205mph (331km/h) top speed, proven three years ago and not exceeded since.

MTM gets the extra performance out of the Continental GT with upgraded exhaust, an engine retune and a few secret tweaks. Other performance upgrades include a special F-Cantronic system that incorporates an electronic system to lower the Bentley by 35mm at the rear and 25mm at the front. Huge 412mm brakes with six-piston calipers stop the massive Bentley with ease.

Twenty-one inch alloy wheels in a classic design match the modern-classic lines of the Continental. The exterior and bodywork are otherwise left untouched.

MTM also offers the Birkin treatment to the Continental GTC, Flying Spur, GT Speed and GTC Speed in addition to the Continental GT pictured here.

MTM Birkin Edition Bentley Continental GT