Compare the Audi A8 3.0 TFSI Quattro - [2010] vs Mercedes SL Class 500SL V8 R107 - [1980]. 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 A8 3.0 TFSI Quattro or the Mercedes SL Class 500SL V8 R107. We'll leave it up to you to decide which is your favourite.