Brabus factory tour.
Basically after AMG have worked on a Mercedes-Benz, Brabus feel the need to add even more power to all of the cars. My parents have a Brabus Smart and although it only has a tiny 1.0L engine, Brabus have tuned it so that you can do over 120mph in it. My dad had the ECU remapped as well so it beats C250s in a straight line. No joke.