The Bugatti Type 51 Dubos Coupe is a one-off automobile originally built by Bugatti in 1931 as an open-top Bugatti Type 51 race car that was driven by legendary racer Louis Chiron, and then modified by Louis Dubos to be a luxury road coupe. It is one of the most valuable cars in the world, estimated at around $20 million dollars as of 2023.

The Twenty Grand is the name given to the one-off custom 1933 Rollston Arlington Torpedo-bodied Duesenberg SJ ultra-luxury sedan. The design's initial price tag of an astronomical US$20,000 during the height of the Great Depression infamously gave it its nickname of Twenty Grand. It is widely considered to be the most famous Duesenberg ever built and the pioneer of the ultra-luxury car design, making it one of the most valuable cars in the world at over $40 million dollars.