the biggest issue with selling US cars is the price.when you are paying close to $100'000 for a converted late model truck,$100'000 plus for a GT Mustang and more for the corvette,camaro,challenger.
Holden did do C20 chev's as factory RHdrive in the mid late 70's.Mustangs were also done in the 60's and early 2000's,by the factory here,the motor was offset to the left and a Festiva (?) rack used.Price and ultimately lack of interest killed the mustang sales.To many people here are hung up on driveing overpowered taxi's.

Tex