Porsche built dedicated cars for each type of racing track. Based upon the lightweight and short Porsche 909 which was used in hillclimbing, the new open cockpit version, the 908/03, was even shorter than the 908/02, and only weighed 500 kg (1,100 lb)- an astonishing figure for a long-distance racing car- in comparison, the 917K weighed about 840 kg (1,900 lb). This version was successful in the 1970 Nürburgring 1000 km and the Targa Florio, where typical speeds were only about half of the which the 917LH long tails could achieve at Le Mans. The 908/02 in which Steve McQueen finished second at the 1970 12 Hours of Sebring was also used as a camera car for the Le Mans film in the race itself. McQueen originally intended to drive a Porsche 917 in the race, though this was vetoed by the studio funding the film. In 1971, vertical fins were added to the rear of the 908s which were beaten at the Targa by Alfa Romeo and their Tipo 33s. All entered 908/03s crashed (two on the first lap; Brian Redman was badly injured after crashing), but Vic Elford had managed to set fastest lap. The next race at the Nürburgring saw a 1-2-3 finish for the 908 in front of two Alfas, but with Alfa scoring wins at Brands Hatch and Watkins Glen, it was proven that these prototypes could beat the 917s. With the combination of the powerful 917 and the lightweight 908, Porsche dominated the International Championship for Makes each year from 1969 to 1971. 1972 - 1981 For 1972, the 5,000 cc Group 5 sports car category was discontinued, and the 917 and its main rival, the Ferrari 512, became obsolete. In the 3,000 cc category, renamed "Group 5 sports cars", Porsche's main advantage was their low weight, as the engine was underpowered with . The new rules required a much higher weight () than Porsche could achieve (well under ), giving the advantage to the Ferrari 312PB, Alfa Romeo T33TT and Matra with their more powerful F1-derived engines that had or more, even in endurance trim. Porsche decided to end its 20-year history of factory sports car racing and sold the 908/03 cars to customers. Besides developing the 917/10 turbo for the Can Am series, the Zuffenhausen-based company focused on the development of the already aging Porsche 911, testing the 911 flat-six with turbochargers.