The logo says "Nels", but I don't think it has anything to do with the car.
Nels is the name of the publishing company in Brussels that made the postcard. If you Google the name you will find many examples of their cards, with the name and logo on both front and back (examples below).
In fact, I think the company still exists today as Nels-Thill SA, Berthelotstraat 156-164, Brussels.