Compare the Vauxhall-Opel Astra OPC GTC VXR 2.0 Turbo - [2012] vs Ford Mustang GT 4.6 V8 Convertible - [2005]. 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 Vauxhall-Opel Astra OPC GTC VXR 2.0 Turbo or the Ford Mustang GT 4.6 V8 Convertible. We'll leave it up to you to decide which is your favourite.