A 1939 Mercedes-Benz 540 K spezial cabriolet is the star lot of RM Sotheby's Amelia Island sale on March 13.
The lot is a unique variant of this highly sought after model. It formerly belonged to American opera singer James Melton, who owned a legendary car collection.
When he began selling off his cars in the 1950s, the 540 K was one of the last to go. In recent years it has undergone an extensive and sympathetic restoration.
Jonathan Sierakowski, car specialist at RM Sotheby's, explains: "This car has all that a superb automobile should have: memorable lines, superb engineering and abundant power.
"Add in its exceptional ownership chain and its bevy of special one-off features, from the raked vee'd windshield to the louvered front hood, special fitted luggage and the five-speed transmission, a feature only seen on the later examples, and it can be rightfully considered one of the most superlative and unique 540 Ks."
It's valued at $3m-4m.
Other lots offered include a 1954 Bentley R-Type Continental fastback sports saloon, which is estimated to make $1.2m-1.4m.
It's the archetypal Continental and has had just four owners from new.
This year's Amelia Island sales look to be some of the biggest yet, with Bonhams featuring a superbly rare 1937 Bugatti Type 57C which has an estimate of up to $13m.
Please sign up to our free newsletter to receive exciting news about classic car auctions.