Speaking of the Commodore platform, how about selling the VZ Monaro in the US as the Pontiac GTO?
The first problem is that the fuel tank did not meet US crash safety standards, so to make it meet them, they had to relocate it to the trunk, like so:

The second problem is that we didn't have the VZ Commodore here, and therefore Pontiac couldn't say that their new GTO was based on a good model that people were familiar with. (Historically, the GTO was based on a mainstream Pontiac model.) I mean, it is a relative of the B1/B2 Cadillac Catera (read: Opel Omega), but that thing flopped so hard in the US... Instead, the styling lead people to believe it was an overbloated Chevrolet Cavalier/Pontiac Sunfire, which is one of the most awful cars that GM has produced in recent memory (they've produced worse, but the Crapalier was one of their most RECENT cars with no redeeming qualities).
There were other oddities due to the VZ not being designed with LHD markets in mind (even though the Omega that it was based on was), as I recall.
It was a nearly complete flop, and honestly, I'm surprised they even brought the Pontiac G8 (VE Commodore) after that flop.