Nevertheless, Renault and other manufacturers had clandestine development programs underway. Here we deal with design work done largely in 1942 on a potential postwar 14 CV Primaquatre (Type 104 E). Source material is from Automobilia hors-série No. 26, Toutes les voitures françaises 1940-46: les années sans salon by René Bellu.
What I find most interesting is the borrowing of styling themes from Pontiac, Hudson and Chrysler by Renault's stylist Robert Barthaud. The United States was neutral regarding the war until late 1941, so information on U.S. cars through 1942 models (introduced fall, 1941) was available in France.
American influence is strong. The main source here seems to be the 1939 Hudson with perhaps a whiff of 1940 Ford. Note especially the front fenders and grill compared to Hudson styling seen in the photo below.
But it's not all Hudson influence. Those sure look like Pontiac's legendary Silver Streaks running down the hood centerline and over the grille.
This narrow version of Silver Streaks is similar to what Renault seems to have borrowed.
Hudson influence disappeared on the second version 104 E prototype and 1941 Pontiac details predominate. Compare to the image below.
The running prototype differed from the drawing in that the Pontiac-like crease across the rear fender was eliminated.
Pontiac influence ceased on the front end and borrowing shifted to 1941 Chryslers, as can be seen in the image below.