When Jaguar E2A, the 1960 prototype XKE racer, crosses the block in August at the Bonhams & Butterfields sale at Quail Lodge, auction officials reckon it could break the bank, and bids in excess of $7m are expected.

The distinctive car is a bridge between the iconic D-type of the 1950s and the equally iconic E-type that heralded Jag's vision for the 1960s and beyond. It is significant not only for that reason, but also because it was raced under the Briggs Cunningham colors at Le Mans and in the SCCA by some noteworthy drivers.

Says James Knight, International Head of Bonhams' motoring department, "Jaguar E2A is absolutely one of the most charismatic and significant prototypes ever produced by the mainstream motor industry, at any time, anywhere. As the taproot of the magnificent E-Type Jaguar series, E2A would be enormously significant for that alone. But when you consider its Le Mans 24-Hours racing history, its association with four such all-time great racing drivers as Sir Jack Brabham, Bruce McLaren, Dan Gurney and Walt Hansgen, it offers pretty much all the finest attributes any connoisseur could ever seek in a road-useable sports-racing classic."

E2A headlines a Bonhams & Butterfields Quail Lodge sale that is already shaping up to be very strong, as another notable consignment includes the 1969 Porsche 908 Spyder of actor Steve McQueen.

The sale takes place Friday, August 15, in Carmel Valley. Visit www.bonhams.com for more information.