In this brand new episode of DRIVE, Matt Farah heads over to Florida to talk to Hartmut Feyhl about his respected tuning company, RENNtech, and to get behind the wheel of a 700 hp Mercedes-Benz CLS 63 AMG. Beneath the hood of this particular animal, the 5.5-litre V8 has been treated to a pair of upgraded turbochargers, optimized ECU software and a new exhaust system.