10. The Bettencourt-Zupan Coupe
The late 1940s marked the beginning of the custom car culture with modified cars first appearing in magazines and car shows. One of the first highly influential models that gained wide recognition was the Bettencourt-Zupan 1949 Mercury. This car was the first customized “Lead Sled” Mercury model that set the template for thousands that came after it. When they built the car, it became popular and was in several magazines. However, by the end of the ’60s, it was outdated. After the original owner died in an accident, they sold it to the famous SoCal customizer Dean Jeffries.

But one night in 1970, someone stole the car in front of his shop and he never found it. The custom car guys are on the lookout for this extremely important, valuable piece of the American car culture. The only trace was a pair of photographs that were allegedly taken in the 1980s. Those pictures suggest the car still exists, but it could be in a private collection.