Compare the Rolls-Royce Phantom Coupe 6.7 V12 - [2008] vs Porsche 944 Turbo - [1989]. 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 Rolls-Royce Phantom Coupe 6.7 V12 or the Porsche 944 Turbo. We'll leave it up to you to decide which is your favourite.