#5: Mercedes-Benz SL-Class
- Style: SL550 2dr Convertible (5.5L 8cyl 7A)
- Combined (city and highway) MPG: 17
- Purchase price: $106,718
- True cost of ownership: $129,588
Mercedes-Benz has been producing its grand tourer SL-Class since 1954. It was not until 2007 that the company debuted the SL550 convertible. Although it is the seventh-most expensive when ranked by purchasing price alone, it ranks as the fifth-most expensive model for overall cost of ownership because of its particularly costly financing interest and insurance. Total registrations of the car have dropped dramatically from more than 5,600 in 2007 to less than 1,500 in 2011.