Matt Farah Drives 700HP RENNtech CLS63 AMG

After 15 years at AMG, Hartmut Feyhl went solo and set up his own tuning company. RENNtech is what he called it, and today it stands as one of the most revered Mercedes tuners around. In the latest installment of the "Drive" web series, Matt Farah tries out RENNtech's 700-horsepower Mercedes-Benz CLS63 AMG, a $120,000 luxury car with room for four, massage seats and the ability to do rolling burnouts thanks to the 5.5-liter V8 that's been given a pair of upgraded turbos, a new exhaust system and optimized ECU software.

From ECU remaps to comprehensive street conversions to full-fledged racers, RENNtech does it all.