As for JD Power's problems per 100 cars it is by individual model, not by brand (they have a seperate listing by brand). Basically the Initial Quality doesn't have anything to do with reliability, it has to do with overall satisfaction with the car at the initial ownership change. The "problems" are things people say they dont like, such as bad cuholders, uncomfortable seats etc. Its a indicator of how satisfied people are with their new cars...
As for the forums, we just had a discussion about this on the Lexus Owners Club board (Frankie, and any other Lexus owner or non Lexus owner alike come on over, we have a real nice community and forum, still fairly small
us.lexusownersclub.com) about the ES Transmission. A lot of people have been saying that the ES has a serious transmission problem (which it doesnt) because of all the posts on the board. As I was telling them, you see a LOT of problems and concerns posted on those forums for a couple of reasons:
1. More people set out to find forums when they're having problems then when they're not.
2. Once a problem is discussed once or twice its on the search engine. In our case anyone who searched for "Lexus transmission" got our site, giving the false impression of a dire situation.
3. People on forums tend to be far more critical and nitpicky than people who aren't
So, while forums are an excellent resource when getting info, and just great for car enthusiasts they aren't always a true representation of whats really going on with a car.