Here is a first list for batch conversion:

AEC GB
Alvis GB
Allis-Chalmers USA
Auburn USA
Austin Healey GB
Auto Union D
Autocar USA
Barkas DDR Flag missing
Bedford GB
Bohemia CS Flag missing
Borgward D
Birstol GB
BSA GB
Bugatti D->F->I->D
Cadillac-Gage USA
Caterpillar USA
Club Car USA
Commer GB
Crown USA
DAF NL
Daimler GB
Dennis GB
Dino I
Divco USA
DKW D
Dodge Brothers USA
Duesenberg USA
E-Z-Go USA
Eagle (car) USA Eagle (bus) is USA
Ebro E
Excalibur USA
Fisher USA
Flxible USA
FMC USA
Foden GB
Fordson GB
Framo DDR Flag missing
Guy GB
Hanomag D
Harley-Davidson USA
Hillman GB
Hispano-Suiza E->F
Hudson USA
Humber GB
Ikarus H
Indian USA
JCB GB
Jeep USA
Jensen GB


I finished a lot of makes with up to 6 cars listed ... but still quite a lot missing.