Ken Tyrrell
It was Crosthwaite's idea to surprise Jackie Stewart by making him a tartan driving seat for his BRM P261 at the 1965 Monaco Grand Prix. Graham Hill finished first and Stewart third. Both Graham Hill and particularly Jackie Stewart liked the way Crosthwaite set up their cars and he was asked by Ken Tyrrell and Matra (Jackie Stewart's next team) to do consultancy work on their Formula 2 cars after he left BRM.