David Clark, 12 Hours of Sebring winner Marino Franchitti, 24 Hours of Le Mans winning Audi Sport Team Joest engineer Howden Haynes, Michael Neuhoff, Dave Ward and former Porsche Carerra Cup GB Champion Phil Quafe share the #351 GMP Developments Stand Up 2 Cancer run Citroen C1 at Copse on the Silverstone Grand Prix layout during the 2019 Trade Team Citroen C1 Challenge 24 Hour race at Silverstone.