can i assume if it's non bose/ non navi, the stock HU can support aftermarket speakers and amps? with hi/low converter and such?

wait, it is too soon.. i haven't even decided on the car yet :D

Who knows? There have been several non-Bose stereos in cars where it's a little more complicated than that too. We'll just have to wait until someone knowledgable can get their hands on it. It would be nice, IMO, if you could get the in-dash changer in the non-Bose system, and simply be able to add amps and speakers.

---jps