Compare the Mini Cooper John Cooper Works Roadster - [2012] vs Audi A6 3.0 TDI BiTurbo Quattro Tiptronic - [2016]. 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 Mini Cooper John Cooper Works Roadster or the Audi A6 3.0 TDI BiTurbo Quattro Tiptronic. We'll leave it up to you to decide which is your favourite.