Compare the BMW 6 Series M6 Gran Coupe 4.4 V8 - [2012] vs Mercedes C Class 63 AMG Edition 507 Estate - [2013]. 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 BMW 6 Series M6 Gran Coupe 4.4 V8 or the Mercedes C Class 63 AMG Edition 507 Estate. We'll leave it up to you to decide which is your favourite.