This car, chassis 85032, is one of only three streamlined Mille Miglia Roadsters with the unique "trouser crease" fenders.
With its aluminum-magnesium lightweight coachwork, it is the only one of the three built entirely by BMW in Munich.
Not only did it win its class in the 1938 Mille Miglia, but it was heavily modified with cutting-edge technology before being entered in the 1940 race where it became part of the five-car championship team.
The Bügelfalte is eligible for the most important and exclusive events and has never before been publicly available.
This example of the 1937 BMW 328 Mille Miglia "Bügelfalte" boasts a 130hp, 1,971 cc inline six cylinder engine - the very same which helped establish BMW's reputation for lightweight, responsive high performance sporting automobiles.
The car's impeccable racing pedigree dates back to its debut, not at an auto show but at the Nürburgring in the Eifelrennen.
There it won its first outing on June 14, 1936, raced by Ernst Henne.
The historic 328 will roll onto the auction block at RM Auctions' anticipated Monaco event on Saturday, May 1.