Some of you may know who VÄTH is as we have seen some tuning work from them before but this has to be their most significant program ever. The Mercedes A45 AMG is already one of the hottest hot hatches around but VÄTH have decided to make it even hotter. They are able to tune the little 2.0-litre four-cylinder turbocharged engine all the way up to 420 horsepower which is a healthy 64 horses up on the standard output. Combined with this performance increase, you can also choose a stainless steel sports exhaust system, coilover suspension to reduce ride height and even some big 20″ wheels to complete the package. I wonder if they give you a warranty on the engine because as far as I know, Mercedes squeezed the safest amount of power out of that engine.