The BOSE in the 350z was utter shite. Really really flat. A bit of bass and pretty loud but it just sounded like everything was being remastered down to 92kbps or something. Like listening to an audio casette!
I have also heard it in several Audi's and found it equally as shite.
I think comparing BOSE to a B&O system is something that would only be done by someone either biased, or that hasn't heard a B&O system.
Andrew's B&O being a possible exception as it's got problems at present of course.
In my experiences within 6 or 7 cars: Bose is alot better than bone standard but alot worse than almost any aftermarket setup or any reputable hifi maker.
If I compare say an Audi TT (Circa 2010) with an E92: I'd put the Bose on terms with the alpine upgrade perhaps, but not as good as HK and nowhere NEAR individual (which still only costs half of the B&O system in Andrew's car.)
Previously: 2003 Peugeot 206 1.6 8v | 2006 E90 320d M-Sport, 19" BBS CH, Full Ice-cold JL audio install, August 2010 Total BMW 6 page feature car. | 2003 Nissan 350Z GT Coupe 286BHP
Now:2010 E92 LCI 335d M-Sport