1931 Bentley 4 1/2 Litre SC "Blower" Sports 2/3 Seater Boattail
High-dollar restorations often mean rebuilding and recreating parts of old cars that didn't survive. What makes this 1931 Bentley nicknamed "The Green Hornet" valuable was that generations of owners have kept as many of its original pieces intact, from the 4.5-liter four-cylinder engine and supercharger down to the fabric roof. It's also one of only 50 "blower" Bentleys ever built, which is why auction house Gooding & Co. estimates it will sell for between $8 million and $10 million.
1968 Ford GT40 Gulf/Mirage Lightweight Racing Car
Successful race cars typically spend so much time on the track that there's not many original parts left when they're retired. This 1968 Ford GT40 in the classic Gulf livery has been through several engines and its original bodywork resides in France, yet the car's still expected to fetch several million dollars when RM auctions puts it up for sale this weekend.
The reason? This car not only ran and won races around the world, with some of the greatest drivers of the era, but was chosen by Steve McQueen to be a camera car for his movie "Le Mans." Despite having its body and engines chopped throughout its life, it's one of the rarest endurance race cars in the world, and the first Ford GT40 to wear the Gulf colors.
1956 Ferrari 250 GT LWB Berlinetta 'Tour de France'
Last year, a 1957 Ferrari 250 TR Prototype set a world-record when it sold for $16.4 million at a Monterey auction; other Ferraris have since doubled that number for the record sale price of any car. This Ferrari, one of nine built, has an odd history -- having been built to race, it was barred from competition, then passed around until it was bought by Walt Disney Studios and used in "The Love Bug." From there it fell into neglect, and was once even abandoned on a California freeway for several weeks. Since then, it's gone through a full Ferrari-approved restoration, and bids will start above $3 million.
It's one of those quirks of classic automobiles that the newest vehicle on this list is also the only one that isn't frequently started and driven. McLaren F1s have already begun their ascent into the stratosphere of collectable supercars, but this racing version was the last of the track variants built -- ones that had to have their 650-hp BMW V-12s de-powered to compete. This car has been priced at $4 million before, and could fetch that in the shopping around Monterey this weekend.