5. Duesenberg SJ-506
Duesenbergs are one of the finest American cars the industry ever built. It is also one of the most respected, sought-after classic cars in the world. The SJ model is the top of the line “Doozy” with a supercharged eight-cylinder engine and an astonishing 320 HP. This was unheard of in the 1930s. Duesenberg only made 26 of them. While they’ve accounted for most of the cars, the chassis number 506 has been missing since the early ’60s.
The car was bodied by the French company Franay, appearing at the Paris Motor Show in 1934. They sold it to Emile Beghain of Algeria, who raced on the Le Mans track, later returning with the car to Algeria. The elegant roadster remained in his possession until 1962 when civil war broke out and Beghain was forced to flee. Although some people think the car was destroyed, there is no evidence of that, so the destiny of the SJ-506 remains a mystery.