Same as the Trucks & Motorbike games. Any car manufacturer past or present.
Austin
B M W
Chrysler
Daimler ( I believe they now own Chrysler 
)
edsell
ferrari
gmc
Hummer 
Isetta
Jensen
I don’t want to be a pedant, but…Edsel was a Ford (named after Henry’s son) and the Hummer is a GMC if I’m not mistaken
anyway
Kurtis Kraft
Jules
lamborghini
Masarati
(if thats the spelling, still starts with an M anyway).
nsu
opel
porsche
Rolls Royce
Subaru
Triumph
Unimog