Compare the Audi A4 S4 4.2 Quattro Cabriolet - [2004] vs Nissan 350Z Roadster 300bhp - [2006]. 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 A4 S4 4.2 Quattro Cabriolet or the Nissan 350Z Roadster 300bhp. We'll leave it up to you to decide which is your favourite.