Wintersteen bought Grand Sport chassis 002 from Roger Penske and picked up his Roadster after the 1966 Sebring race. The Wintersteen Roadster was immediately updated by Traco with a 427 ci engine equipped with a single Holley carburetor.
Competing in the 1966 US Road Racing Championship, Wintersteen and chassis 002 delivered impressive results at Bridgehampton, Watkins Glen and Mosport, given that the competition was now two years ahead and far more sophisticated.
The 1966 USRRC event at Watkins Glen, in particular, stands out from the other races. George remembers being bumped by Charlie Parsons' McLaren before moving over to give Parsons the racing line. "The next thing I knew, Parsons was off in the weeds amid great clouds of dust," Wintersteen recalls. He does not, however, recall stopping his Corvette to pull Mark Donohue from his crashed and burning Lola T70!