I shipped my car several times back and forth between USA, Europe, and Australia because the rental cost would have been more than the shipping cost.
RoRo shipping my car cost round trip $1,600 last year USA/Europe plus $300 insurance rider.
Three month rental, plus rental insurance versus rider on my insurance? Rental would be approximately $3,100 car and about another $1,800 for insurance.
There's no registration headaches about the car not meeting the differing safety/emissions regulations in the different markets? It seems like its a massive hassle for people to even bring kei cars from JP to US, I routinely hear about how expensive it is to import cars across markets.