As stated before, limited models for each brand. Buick was the (I beleive) doctors car, pontiac little more pricier and expensive than a chev, etc. Idea, as stated, when done with a chev, moving to a bigger car (nest size or "tier") a cust went to pontiac. Not sure when but that changed to the mentality that chevy would affer their entry level cars all the way up to the "luxury" vehicle and pontiac, and the rest the same. That started the trend of sharing platforms and vehicles, and engines, drivelines, etc thus doing away with the "tier" thing and overloading the market with many diff but same cars thus leading to the slow sales of certian makes, such as plymouth, olds, now pontiac and trimming down the offerings to something that will be like what (I suspect given time) will be back to something similar to what was back in the 1900's. Acura, infinity, and those luxury brands are only available on this side of the water. The "Acura" nsx was a honda in the rest of the world
