In 1971 the then Brands Hatch MD, Jon Webb, organised a race that pitted F1 Grand Prix drivers against their team managers in Ford Escort Mexicos. This event was a graet success and this led to Ford loaning Webb twenty mechanically identical Mexicos in Febuary 1973. After sponsorship had been obtained from Shellsport and Avon Tyres the cars were known as the Shellsport Mexicos and ran on Avon cross-ply tyres which were inflated to 45psi. Modifications to the cars were carried out at Ford AVO facility in Aveley and were limited to the fitting of Britax three point harnesses, Bilstein shock absorbers, roll cage, battery cut off and four spoke RS alloy wheels.