Question: Günter "Bobby" Klass was a factory driver for a company that has been successful in many branches of motorsport of which most have been in what?

full_context: Document 1: Bobby Unser: Robert William "Bobby" Unser (born February 20, 1934) is an American former automobile racer. He is the brother of Al Unser, Jerry Unser and Louis Unser, the father of Robby Unser, and the uncle of Al Unser, Jr. and Johnny Unser. He is one of ten drivers to win the Indianapolis 500 three or more times, and one of only two (followed by Rick Mears) to have won the 500 in three different decades (1968, 75, 81). Bobby has also been a spokesman and advocate of many commercial products.
Document 2: Gerhard Berger: Gerhard Berger (born 27 August 1959) is an Austrian former Formula One racing driver. He competed in Formula One for 14 seasons, twice finishing 3rd overall in the championship (1988 and 1994), both times driving for Ferrari. He won ten Grands Prix, achieved 48 podiums, 12 poles and 21 fastest laps. With 210 starts he is amongst the most experienced Formula One drivers of all time. He led 33 of the 210 races he competed in and retired from 95 of them. His first and last victories were also the first and last victories for the Benetton team, with eleven years separating them. He was also a race winner with Ferrari and with McLaren. When at McLaren, Berger drove alongside Ayrton Senna, contributing to the team's 1990 and 1991 constructors titles.
Document 3: Porsche: Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche AG (] ), is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans. Porsche AG is headquartered in Stuttgart, and is owned by Volkswagen AG, which is itself majority-owned by Porsche Automobil Holding SE. Porsche's current lineup includes the 718 Boxster/Cayman, 911, Panamera, Macan and Cayenne.
Document 4: Klenk: The Klenk-Meteor was a racing car which competed in the 1954 German Grand Prix. The car was based on the established German marque of Veritas which was active between 1948 and 1953. Veritas is chiefly remembered as a manufacturer of sports cars and successful Formula Two racing cars. The company closed when its founder, Ernst Loof, became ill. He subsequently died in 1956. The Klenk-Meteor entered for the 1954 German Grand Prix was essentially a Veritas Formula Two car. The car was owned and prepared by the noted German racing driver Hans Klenk who intended to race it himself in the Grand Prix. However, Klenk's career as a racing driver came to an end when he suffered injuries in an accident while working as a test driver for Mercedes-Benz. The car was driven in the Grand Prix by another German, Theo Helfrich. He retired on lap 9 with engine failure.
Document 5: Formula One drivers from Germany: There have been 52 Formula One drivers from Germany including three world champions, one of whom is currently racing in the sport. Michael Schumacher holds many records in F1 including the most world championship titles and the most consecutive titles. In 2008 Sebastian Vettel became the youngest ever driver to win a race (which was later broken) and, in 2010, became the youngest world championship winner. In 2016, Nico Rosberg became the third driver from Germany to win the F1 drivers' championship. There are currently three German race drivers in Formula One.
Document 6: Porsche 919 Hybrid: The Porsche 919 Hybrid is a sports-prototype racing car constructed by the German car manufacturer Porsche for use in the Le Mans Prototype 1-Hybrid (LMP1-H) category of the FIA World Endurance Championship for factory-supported hybrid-powered cars. It is the first sports-prototype built by Porsche since the RS Spyder, the first sports-prototype built by Porsche to compete in a top category of sportscar racing since the Porsche 911 GT1-98 and Porsche LMP1-98 and the first sports-prototype to be raced by Porsche as a racing team since the Porsche 911 GT1-98 and Porsche LMP1-98. It uses a 2.0 L four-cylinder turbocharged engine with a battery-based hybrid system. The car made its competitive debut at the 2014 6 Hours of Silverstone, the opening round of the 2014 season. The 919 Hybrid project is scheduled to be discontinued at the end of the 2017 season to allow Porsche to focus on entering Formula E.
Document 7: Porsche RS Spyder: The RS Spyder (Type 9R6) is a racing car designed by Porsche in conjunction with Penske to compete in Le Mans Prototype Class 2 (LMP2) racing. The car takes its name from the legendary 550 Spyder of the 1950s (combined with Porsche's common "RennSport" "(lit.: racing sports)" designation). The car marked Porsche's first return to the top level of sports prototype racing since the firm abandoned its Porsche LMP in 1999.
Document 8: Günter Klass: Günter "Bobby" Klass (13 June 1936 in Stuttgart – 22 July 1967 near Florence) was a versatile German racing driver, competing in hillclimbing, rallying, and the World Sportscar Championship as factory driver for Porsche and the Scuderia Ferrari.
Document 9: Maserati in motorsport: Throughout its history, the Italian auto manufacturer Maserati has participated in various forms of motorsports including Formula One, sportscar racing and touring car racing, both as a works team and through private entrants.
Document 10: Need for Speed: Porsche Unleashed: Need for Speed: Porsche Unleashed, released as Need for Speed: Porsche 2000 in Europe, is a racing video game released in 2000. It is the fifth installment in the "Need for Speed" series. Unlike other "NFS" titles, "Porsche Unleashed" centers on racing Porsche sports cars, with models ranging from 1950 to 2000. The game is noted for its extensive information regarding Porsche and its cars. Unlike the previous four "Need for Speed" games, "Porsche Unleashed" was not released in Japan.
Document 11: 1974 German Grand Prix: The 1974 German Grand Prix was a Formula One motor race held at the Nürburgring on 4 August 1974. It was race 11 of 15 in both the 1974 World Championship of Drivers and the 1974 International Cup for Formula One Manufacturers. It was the 36th German Grand Prix and the 33rd to be held at the Nürburgring complex of circuits. The race was won by Swiss driver Clay Regazzoni driving a Ferrari 312B3. Regazzoni led every lap on the way to his second Grand Prix victory, some four years after his debut victory at the 1970 Italian Grand Prix. South African driver Jody Scheckter was second driving a Tyrrell 007 ahead of Argentine driver Carlos Reutemann (Brabham BT44).
Document 12: Clay Regazzoni: Gianclaudio Giuseppe Regazzoni (5 September 1939 – 15 December 2006), commonly called "Clay", was a Swiss racing driver. He competed in Formula One races from 1970 to 1980, winning five Grands Prix. His first win was the Italian Grand Prix at Monza in his debut season, driving for Ferrari. He remained with the Italian team until . After a single season with BRM, Regazzoni returned to Ferrari for a further three years, to . After finally leaving Ferrari at the end of 1976, Regazzoni joined the Ensign and Shadow teams, before moving to Williams in , where he took the British team's first ever Grand Prix victory, the 1979 British Grand Prix at Silverstone.
Document 13: Dauer 962 Le Mans: The Dauer 962 Le Mans is a sports car based on the Porsche 962 racing car. Built by German Jochen Dauer's Dauer Racing, a racing version of this car went on to win the 1994 24 Hours of Le Mans with the support of Porsche through the use of regulation loopholes.
Document 14: Porsche in motorsport: Porsche has been successful in many branches of motorsport of which most have been in long distance races.
Document 15: Porsche Carrera Cup Germany: The Porsche Carrera Cup Germany, also known as Porsche Carrera Cup Deutschland, between 1986-1989 as Porsche 944 Turbo Cup; is a one-make racing series by Porsche based in Germany.
ground_truth: long distance races