So After looking at several different options I decided on a F90bt. I recieved it today, refurbed, ebay, for $450 shipped. I am very excited, I have had better sounding decks (macintosh HU) but never had one that does more. I have yet to install it though.

I wonder, do I need some special adapter to hook it into my car wiring and use the oem car speakers? I have a MazdaSpeed3 with the BOSE package. I have the Metra kit, PAC SWI-PS for the steering wheel, metra wire harness. I am wondering about the BOSE (crap) amplifier and hooking up a head unit to the speaker wires that has decent power. Crutchfield seems to think I can just hook up the wire harness and it will all work fine. I looked on the Metra site and it has just the one for all Mazdas from 01 and up...

Updates?

If your Mazda is anything like my Acura with the Bose premium package my f900bt did not power my bose sub. You can however purchase a kit that allows the avic to run all the bose speakers. It has something to do with the way bose processes the signal. It goes out of the head unit into a signal processor before the sub. I don't remember where I found the kit sorry.