Jean Graton is such a good writer, and the drawings in the books (BD, for Bande Dessiné, we call them here in France) are so cool too.
The last one is focused on the team Vaillante racing in WTCC, Vaillante being the brand that sells the car that Michel Vaillant uses. In the book, Vaillante is the fourth french car maker, and the cars really are awesome.
I can't find a list of all the cars that Vaillante made through out the books, though I can show you the one they made for real :
It's called the Grand Défi and it's based on some other french cars like an Homell for the chassis and a Peugeot 306 S16 for the stuff that makes everything works.