#1: BMW Nazca M12

Price: $1.1 million – $3 million

The Nazca M12 concept car was designed by Giorgetto Giugiaro for Italdesign in 1991 but never went into production. It features a carbon fiber body and BMW’s best engine at the time, the V12 used in the 750i and 850i.

BMW followed the M12 with the Nazca C2 in 1992, and while only 3 were ever made, the original still draws the most interest from aficionados. In 2011, a collector put an M12 on the market for a listing price of about $1.1 million, and the estimated price has only increased since then.