Ferrari GTO's are now in a class by themselves in the car collecting world. Prized by super-rich collectors for their racing history and rarity (Ferrari made only 36), prices for top GTOs have soared from under $10 million in 2000 to over $50 million today. While a GTO recently traded for $52 million in a private sale, there hasn't been a GTO offered at a public auction in well over a decade.
Read MoreThe $4 million Lamborghini Veneno's maiden voyage
"This quite likely will become the most expensive car at auction," said Marcel Massini, the Switzerland-based Ferrari historian and collecting advisor. "The market right now is just so strong."
Bonhams looks set to break that record again. The GTO it's selling was the 19th made by Ferrari and it was delivered in 1962 to a French racing driver, Jo Schlesser. The car came in second in the 1962 Tour de France.
Read MoreMembers-only racetrack touts luxe $1M garages
But the car crashed during a race at Montlhéry, near Paris, in October 1962, killing the driver Henri Oreiller. Many GTOs have crashed, been repaired and sold for sky-high prices. But the Schlesser GTO is believed to be the only GTO to be involved in a fatal crash, which could affect the price.
"We have to be realistic," Massini said. "That accident could turn some people off. But others may not care, because how many times are you going to be able to purchase a GTO with such a long ownership history."