take a listen to a bose home theater... then listen to a comparably priced home theater system... say with Polk, Boston... etc. speakers, using good components, say from Denon. You're gonna spend about the same money, but the "custom built" system is gonna sound 10 times better.
They use tiny, cheap, paper speakers in those "dual cube" speakers... no actual tweeters, just full-range drivers... and when they do use tweeters (say in the 301 series speakers) they are cheap cone tweeters. All ingredients for making a typical "boom box" stereo... no quality components.
The car stereos follow the same crappy guidelines... very little power, cheap paper speakers... and the same classic crappy sound. They have a way with equilazition, that makes their speakers sound some-what decent... but they are no comparision for REAL speakers...
Bose is just a marketing scam... they take CHEAP products, and spend millions on marketing, so people "think" they are a great product... then they jack up the prices, so again, people think they are buying a quality product... they're wrong. Bose is a total joke.