It's important to make sure that collectible cars have their original major components, colors, and other details if the seller is advertising it as 'original.' Matching numbers prove that the car wasn't pieced together and help cars maintain their value. "If someone just says it's all original, it really doesn't mean anything." Sarcona says. "About 80 percent of the time, if it's advertised as matching numbers, it's not. People say dealers are shady, but most individual sellers are selling their cars for a reason."

No matter how educated you are about a vehicle, you should pay for a prepurchase inspection, according to Sarcona.