My non-NAV TCH also had the stereo set for max bass when it was delivered. I wonder if this strange setting is from the stereo factory, from Toyota, or from ill-considered dealer prep?

I also wonder whether at least a few of the complaints I've seen about the sound quality might be because the bass/treble settings are weird and have not been fixed. Mine is not the best car stereo I've ever heard, but it's way better than average (I rent 35-40 cars per year on business, and I travel with a CD collection, so I've heard LOTS of car stereos for comparison!).