This site gives what looks like a remarkably comprehensive list of all the road vehicle models featured in the Tintin books.
http://mapage.noos.fr/dardelf3/tintin/ListeAutos.html
I found it by googling "Tintin DAF", following yamilah's helpful clue, and learned that the coach that they "borrow" from the Jolly Follies in
Tintin and the Picaros is a DAF Autocar Jonckheere.
They list it as being on page 54 of the book, though it features across several pages of course.
I'd thought of the DAF company earlier, as the only Dutch road vehicle company I knew, but I was looking at the cars and gave up on that idea too soon! (I thought of Fokker aircraft too but couldn't find any of those in Tintin.)