Compare the Ford Mustang GT 5.0 V8 Convertible - [1987] vs BMW 8 Series 840Ci 4.0 V8 2d Auto - [1993]. 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 Ford Mustang GT 5.0 V8 Convertible or the BMW 8 Series 840Ci 4.0 V8 2d Auto. We'll leave it up to you to decide which is your favourite.