German-Tuning firm G-Power has launched a new and improved version of their aftermarket program for the 2013 BMW M6. The 2013 G-Power BMW M6 develops 640 hp and 777 Nm of torque thanks to the Bi-Tronik III kit. It's also able to rocket from zero to 62 mph (100 km/h) in 3.8 seconds and can reach a top speed of 197.5 mph.
No word on a price, but our guess would be at least 50k above the MRSP of a stock M6.
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