It’s been a while since we last heard of German tuner Carlsson and its wild C25 supercar loosely based on the Mercedes-Benz SL platform. At last year’s Geneva Motor Show Carlsson first took the covers off the C25 and announced a limited production run of just 25 units of the V-12 powered beast.

At this week’s 2011 Geneva Motor Show, Carlsson is back and has brought with it a new edition of the C25 dubbed the Royale. Once again limited to just 25 units, the new Carlsson C25 Royale is essentially a lighter yet more well-appointed version of the original C25.

Engineers have managed to shave nearly 400 pounds from the curb weight of the C25, with the new C25 Royale tipping the scales at 4,343 pounds. A new carbon fiber roof also helps lower the car’s center of gravity and a host of various aero mods helps boost downforce.

Under the hood is a 6.0-liter twin-turbocharged V-12 engine that delivers 753 horsepower and up to 973 pound-feet of torque, all of which is sent to the rear wheels via Mercedes-Benz’s heavy-duty SPEEDSHIFT five-speed automatic transmission.

Acceleration is a bit less than you might expect with such insane numbers, clocking 3.7 seconds to 62 mph. The 219 mph top speed is more in line, however, suggesting acceleration from a stop is hampered by traction--not uncommon with a high-torque, rear-driven car--despite huge 12-by-20-inch rear wheels shod with 325/25 tires. The front wheels are 9.5-by-20-inchers that predict a bias toward understeer--until the go pedal comes down, that is. The wheels are also super light for their size, weighing in at just under 25 pounds. Massive 15.9-inch front and 14.9-inch rear brakes get ducted for maximum performance.

Inside, the C25 Royale gets a luxury treatment befitting the car's bespoke status, complete with real carbon fiber, buffalo leather, ultra-suede and a trapezoidal geometric theme.

Pricing starts at approximately $594,204 before shipping and taxes are involved, and in order to keep its new C25 Royale as exclusive as possible, Carlsson promises to deliver just one car per country.

For our complete coverage of the 2011 Geneva Motor Show, click here.