Compare the Audi TT RS 2.5 Turbo - [2018] vs Mercedes CLS Class 63 AMG Shooting Brake - [2012]. Find out which car is the fastest, most powerful, lightest or has the biggest engine in our top trumps style comparison page. Find out which car has the highest top speed or is the fastest accelerating, is it the Audi TT RS 2.5 Turbo or the Mercedes CLS Class 63 AMG Shooting Brake. We'll leave it up to you to decide which is your favourite.