Hi there,
I have 4 names for you.
A Jacques Jaeger has supposedly build in 1904 a car.
A Jean Kesseler has build a sports car Austin-Healey look-a-like car (possibly more, not sure)
Guy Negre started his air car company MDI in Luxemburg
And I have "Fabrique de Voitures Jean Wagner", nowadays a Mercedes-Benz dealer.
Possibly one could include the TAG Croco, production was in Germany though.