Approximate dollar difference: $6,848,000 (Assuming #1 condition)
Annual rate of return: 9.6%
Mercedes-Benz 300-SL Gullwing. Former works car, aluminum body, four-spoke factory wheels. This car is the only Gullwing in existence with the roadster-type rear axle. Just overhauled and completely restored by Mercedes factory. Price $6,500 firm.
Simply put, the 300 SL is high on the list of all-time greats. Its groundbreaking styling, performance, and technology made it an instant success, and today it is one of the most collectible cars from the 1950s. At the heart of the 300SL is a 3.0-liter overhead cam inline-six engine utilizing a groundbreaking Bosch direct fuel injection system. While this technology is common today, in the 1950s it had never been seen outside of aircraft use. This delivered noticeable power gains over the standard 3.0-liter Mercedes engine, making the 300 SL the fastest production car of its time. These cars saw a sharp increase in value between late 2011 to 2014, and the growth was even more pronounced for alloy-bodied cars like this one. For any serious Mercedes collector, the alloy-bodied Gullwings are a prized centerpiece. Luckily for those shopping for one in 1964, an SL was still a decade-old used car and could be had for a bit more than a well-optioned Corvette at the time. Wild.