You know, I wonder if another factor isn't ego? I mean, if I buy a Japanese car known for reliability and have problems, well I'll blame the manufacturer and bitch at them. But if I buy from an American car brand that is (perhaps unfairly) known for poor quality/reliability, and it turns out to have problems, I'll be kicking myself and probably taking a few shots from friends, too, who'll be wondering why I bought a known poor quality/reliability brand. Of course, this is a minor and silly reason to base a decision on, but people do make decisions based on such minor, silly concerns.
Probably is a factor.... there is a known relationship between what someone believes when they purchase and how they view the product after having it for awhile....
1) For example, someone buys a Toyota believing it is high quality. 100k miles later, it is running strong, so that reinforces their idea that it is high quality.
2) Someone else buys a Toyota believing it is high quality, but has a few minor problems, but nothing major. So they again reinforce their belief of high quality.
3) Someone else buys a Toyota believing it has high quality but it has problems. But they know other people who have had no problems, so they assume they "just got a lemon" and try again. As 90% of Toyotas are trouble free, they get a good one the second time around and partially discount the first experience.
4) Someone buys a Ford thinking it is low quality. They have a few minor problems, which reinforce their expectations. They may consider another later, but they're leery, even though it wasn't necessarily worse than a Toyota.
5) Someone else buys a Ford thinking it is low quality. Say 89% are fine. But they get a lemon. Therefore Fords are terrible, and they buy a Toyota the next time. Odds are they'll get a good one, then complain to all their friends about "that p.o.s. Ford" and rave about the Toyota. Yet statistically, the odds were almost identical that they would get a good Ford or a good Toyota (this is pretty close to reality). Therefore, the general public perception is reinforced, but not in a fair manner. It takes many years for this to play out and for the public to recognize that quality may be nearly equal