This car competed in the Grand Prix Masters race at the Silverstone Historic Tribute race in June 2004.
It's the 1976 McLaren M23/6 that James Hunt drove to win the World Championship in that year. The M23 in its effective 4-years of racing won the Drivers' World Championship for Emerson Fittipaldi in 1974 and for James Hunt in 1976, and the Constructors' World Championship in 1974. It was driven in this race at Silverstone by Lorina McLaughlin.
Here's Lorina McLaughlin at Luffield corner during the race leading the 1971 Surtees TS9B of Peter Austin.