Carnut's closed car has coved fender eyebrows front and rear. The clay model in the other puzzle I posted has them on the rear only. Probably one of dozen of variations on a similar theme.
Just as Raymond Loewy headed the design team for the '53 Studebaker - which coincidentally was largely drawn by Exner - and Bob Nixon drew the 1968 Javelin and AMX while part of Dick Teague's team at AMC, the head of the design studio often had their name associated with cars designed largely by others. That's true of other arts, as well. How many great orchestra's are best known by the name of their conductors? Never mind that the virtuoso's on every instrument had practiced their craft for years to make beautiful music.
I expect Samsen's sketches were selected by Exner and the Chrysler brass as a design to develop further. That's an unfortunate development, as that was one of the darker period of Chrysler design, IMO.