Compare the Audi A3 S3 2.0 Turbo S-Tronic Sportback - [2012] vs BMW X6 xDrive50i 4.4 V8 F16 - [2017]. 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 A3 S3 2.0 Turbo S-Tronic Sportback or the BMW X6 xDrive50i 4.4 V8 F16. We'll leave it up to you to decide which is your favourite.