Made by Renč Chaix in the late forties on a Simca 5 chassis?
Another point to you! It's a F3 500cc car built by Rene Chaix in 1949 powered by a Simca Cinq motor.
Chaix has been on AP before - he built a Simca powered sports car and according to a well-known site about F3 cars, this single-seater was built from parts of that sports car. There's an old saying "you've never seen those two people in the same room" but in this instance we have. This photo proves that website is wrong.