with Jo Schlesser in the 1964 24 Hours of Le Mans, but was forced to retire due to the car catching fire. His first major international sports car victory came at the 1964 Rand 9 Hours race in South Africa, driving David Piper's Ferrari P2. It was with David Piper that Attwood developed perhaps his longest lasting professional relationship. He drove Piper's green Ferraris – including the 250LM and 330P3/4 – on many occasions over the following five years, collecting a few point finishes in World Sportscar Championship events, and paired up with Piper for the Maranello Concessionaires team. Highlights during this time included a third place in the Spa 1000 km and second in the 500km Zeltweg in 1967. Attwood did not restrict himself to Ferrari and Ford though, putting in drives in machinery as diverse as the Porsche 906 and Alfa Romeo T33. He was also one of the few drivers to race the infamous Ford P68, GT successor to the GT40, failing to finish due to mechanical maladies during the 1968 1000km Nürburgring. Having driven privateer Porsches, for the 1969 World Sportscar Championship season Attwood was signed to the Porsche works team. Commonly paired with fellow Brit Vic Elford, the season's highlights were a pair of second places, driving the Porsche 908, in the BOAC 500 (the drivers' home race at Brands Hatch) and the Watkins Glen 6h race. Later in the season Attwood was again involved in the development of an iconic sports racing car: the Porsche 917. The Elford/Attwood pairing took their 917 up to 327 laps in the 1969 24 Hours of Le Mans, but the car suffered a gearbox failure with only two hours to go, after leading for a substantial portion of the race. Attwood subsequently went on to win the Le Mans 24 Hours in 1970 with a Porsche 917K, along with Hans Herrmann. Hermann and Attwood also took second place in the 1970 Nürburgring race, this time back in a 908. Driving with Herbie Müller once more in a Porsche 917 he finished second in the 1971 24 Hours of Le Mans, this time for the John Wyer privateer team. At the end of the season, after also winning the 1000km Zeltweg race along with his teammate Pedro Rodríguez, Attwood retired from motorsport. Attwood came out of retirement briefly in 1984, as a part of the moribund Aston Martin Nimrod