<prompt> Pedzisa mutsara unotevera: Muna 1974, Postlethwaite akagadzira motokari itsva yechikwata, Hesketh 308, iyo yakanga yakagadzirira Silverstone International Trophy, iyo Hunt yakakunda, ichiita chikwata chayo chekutanga kuSouth African Grand Prix. Motokari yacho yakanga yakasimba, ichitora nzvimbo yechitatu muSweden Grand Prix, muAustria Grand Prix uye mu  <response>: United States Grand Prix. Nokuda kwa 1975, mienzaniso ye308 yakatengeswa kuna Harry Stiller Racing, uyo akapa Alan Jones mubayiro wake mukuru wokutanga. Polar Caravans vakatengawo Hesketh chassis, apo vashandi vakachinja 308 yeHunt. Panguva imwe cheteyo, Horsley akanga achikura kuva mutungamiriri weboka anobudirira uye anokwanisa uye achitungamirirwa naye, boka racho rakafambira mberi. 