Those H2 hummers with the Bose package sound very good, also my wife's Hyundai Santa Fe, came with 4 6.5's and 2 tweets in the a-pillars and a factory amp to power them,vrey good imaging!
The best factory sound systems come in the cars that don't need electronic sound systems. I could drive those cars around without ever touching the radio.
for what it is scion tcs have decent systems.. girlfriend has it and for not a premium system it sounds decent.. 2005 maxima bose system.. friend has one.. sounds very nice for stock