Is '97 A4 non-Bose vs Bose console different?
 

Crutchfield says I could replace my Delta with a Blaupunkt Bremen if I had Bose, but can't if I don't. (I don't) Saw an archived comment that the only difference in the systems was amps & speakers, but 'they' think there's an obstruction w/o Bose. Anybody know if that's true?

The head unit is the same HU, Bose or non Bose, just coded differently
 

The Bose system uses a 4ch amp to power all speakers, the non Bose just uses a rear amp with the fronts powered off the speaker outs on the HU itself. All I can think is that the Bremen doesn't have any front speaker outs, which is bizarre, but the only possible reason you wouldn't be able to use it (without adding a small amp for the fronts).

Thanks. It does seem strange there would be any less room after the HU was out.