Compare the Radical RXC 3.7 V6 - [2014] vs Audi R8 Performance 5.2 V10 - [2020]. 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 Radical RXC 3.7 V6 or the Audi R8 Performance 5.2 V10. We'll leave it up to you to decide which is your favourite.