Compare the McLaren 540C 3.8 V8 Twin Turbo - [2015] vs Seat Leon ST Cupra 280 DSG - [2015]. 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 McLaren 540C 3.8 V8 Twin Turbo or the Seat Leon ST Cupra 280 DSG. We'll leave it up to you to decide which is your favourite.