Don't forget Mazda's Eunos. Don't/Didn't they have about six brands in Japan? The only other one I can think of off hand is Autozam.
We had a funny little plan in .au in the early 90's called the Button plan (named after the senator who instituted it). I think it was supposed to help improve the profitability of the Oz car industry by increasing platform and common part sharing among local manufacturers. Or something.
In reality it gave us a Holden Commodore badged as the Toyota Lexcen, a Nissan Pintara badged as the Ford Corsair, Toyota's Corolla and Camry badged as the Holden Nova and Apollo. And the Ford Ute badged as the Nissan Ute. Nice one, that. Still, it proved you could raise the value of your ute simply by taking to the big 'NISSAN' vinyl letters on the tailgate with a hairdryer 'til they peeled off.
Sheetmetal changes were minimal at best, and no-one was particularly fooled. Except people buying Mazda 626s as Ford Telstars, but that one had been going on (successfully) for ages before the Button plan.
Mazda gave up on the Eunos brand here a year or two ago, after nothing much spectacular happened with the 30x and the 800? 500?, er, whatever the Mazda Millenia was called. Infiniti put in an appearance for about 10 minutes, too.