Compare the Porsche Panamera 3.0 V6 Turbo Diesel - [2011] vs Vauxhall-Opel Astra 2.0 Turbo SRI - [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 Porsche Panamera 3.0 V6 Turbo Diesel or the Vauxhall-Opel Astra 2.0 Turbo SRI. We'll leave it up to you to decide which is your favourite.