Compare the Pagani Zonda Roadster - [2003] vs Alfa-Romeo Giulia Quadrifoglio 2.9 V6 Bi Turbo - [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 Pagani Zonda Roadster or the Alfa-Romeo Giulia Quadrifoglio 2.9 V6 Bi Turbo. We'll leave it up to you to decide which is your favourite.