How 'loyal' are most people, then? I see the infrequent ad for a discount on the next Ford or whatever for people who own Fords, but it's not like a frequent flyer program or one of those loyalty points clubs- for most people, car buying is a very infrequent and important thing, so rewards for multiple purchases would have to be substantial.

There will always be some people who pick a brand and stick to it, but how typical is that and what's really going on there? (meaning- do repeat buyers come back because of actual loyalty or because of some other consistent factor like price, reputation for safety, quality or durability that leads to the same reasoned choice the next time? Don't many people who own multiple cars own more than one brand, too? So what would that do to the theory?) Just curious.