Car runs from 0-62 miles per hour in 3.7 seconds.

The BMW M4 Convertible is one of the most engaging four-seaters on the market but that hasn't stopped G-Power from trying to improve things.
Starting under the hood, the tuning firm installed a Bi-Tronik 2 V1-ECU remap to increase the output of the 3.0-liter BMW M TwinPower Turbo six-cylinder engine to 520 horsepower and 516 pound-feet of torque.  That's a pretty impressive increase of 89 hp and 110 lb-ft of torque but G-Power didn't stop there as employees also installed a larger turbocharger, new downpipes, and a titanium exhaust system with carbon fiber finishers. 
Thanks to all the aforementioned modifications, the convertible produces 600 horsepower and 545 lb-ft of torque - an overall increase of 169 hp and 140 lb-ft of torque.  Thanks to the extra power and the removal of the speed limiter, the car can accelerate from 0-62 miles per hour in 3.7 seconds before hitting a top speed in excess of 198 mph.
To keep things under control, the model has been equipped with a coilover suspension and 21-inch G-Power Hurricane RR forged alloy wheels wrapped in high-performance tires.
The components can be bought individually but the modifications to this particular car cost over $25,295 (€22,332).
Source: G-Power