Compare the Vauxhall-Opel Viva Brabham 1.2 8v - [1967] vs Mercedes 300 S Roadster - [1951]. 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 Viva Brabham 1.2 8v or the Mercedes 300 S Roadster. We'll leave it up to you to decide which is your favourite.