I just installed the BT45 in my '05 last weekend. Install went pretty smoothly. Running wires through there with average sized man hands is kinda tough. Would be much easier w/ 6y/o hands. I have the same problem with the volume, have to turn it up fairly high on the stereo, but sound is great. Can't remember where I set the dip switches, but mine plays on CD #4. I have satellite and rear DVD in mine. For the head unit, I just pulled the glove box and put it behind the right side of the plastic housing behind the glove box. Didn't even need to secure it (yet).
Not sure if anyone else is running the microphone, but I ended up putting it right under my speedo in the far lower right corner of the instrument panel. Black on black, so it's barely noticeable, even if you're looking for it.
I put my mic in the upper corner of the windshield. Sounds good from what I’m told on the other end of the line and out of sight unless you’re looking up there.
I stashed the box under the shifter console panel. No rattles or anything.