The McQueen film car is a 1968 Gulf/Mirage Lightweight Racing Car, chassis no. P/1074. It saw actual race use in 1968 before spending time in the film business. The second car is a nearly all-original 1967 Ford GT40 Mk I, chassis no. P/1059. According to RM Auctions, it's regarded as one of the most original GT40s in existence.
The Gulf/Mirage GT40 was raced at Le Mans trials by Jacky Ickx, and by others at Daytona and other venues before being sold to Solar Productions, where it was used as a camera car (!) for the 1970 film Le Mans starring McQueen. Since then, the car has passed through many hands, but was always shown and run. In 2000, it was restored in detail.

1967 Ford GT40 Mk1. Photo courtesy of RM Auctions.
The RM Auction Monterey auction will run August 17 and 18, starting each evening at 6 p.m. The auction can be previewed from 10 a.m. to 6 p.m. August 15-16 as well as 10 a.m. to the end of sale on the auction dates.