Since I currently have all of the stereo equipment out of my 240z I am tossing around some ideas of what I want.  I have an original and working auto-seeking AM radio for my car that works and would really like to install it as I think it makes the car look period correct and I could use the power antenna switch to raise and lower the antenna.  However, when I drive the car I would like to listen to FM radio as AM does not offer much and utilize Bluetooth when needed.  I have a nice Alpine AM/FM/CD/MP3/BT stereo that I have been using but I never use the CD player, really just FM and BT.  My question is, could I install the AM radio in the stock location and install a CD-less BT stereo receiver in the glovebox and use a remote to change the stations when I wanted?  What would be the best way to divide the speaker output?  I plan on fabbing up some brackets to place two 6.5" speakers behind the rear cargo panels just like where the factory 5.25" speaker was.  I would think I would need a switch to move power from one unit to another or it is possible both could be powered on and I could just have some sort of speaker switch that would go from mono for the AM and stereo for the FM/BT unit.  Do you guys have any experience with Bluetooth FM only receivers?  All ideas, feedback, suggestions, and pictures welcome!  Thank you!

I would run the signal seeker on a seperate small 4 ohm speaker.  That thing wasn't designed to run modern speaker(s) 

That radio is rated @ 4 watts output.

You can get an antenna splitter to run 2 radio's on one antenna.

Thanks hr369.  After some more thought I think I am just going to run the AM radio with a new 5.25" speaker.  I really do not drive the car that much and if I reach a point that I want FM and BT then I can cross that bridge when I get there.