opel cars touring races other germany nuerburgring 1971 1972 6h finthen mainz 1973 salzburg steinmetz austria hi res 24h belgium francorchamps spa 1 formula light rikky two von blur fighting italy speed a4 commodore dieter ensign florio ford froehlich sport targa calascibetta monti paolo salvatore 1974 britain great others silverstone zeltweg 1975 a3 castellet chevrolet fans france front hockenheim jump le many monza porsche rear smoke three zoom