Over the weekend I was able to take out the factory radio, take that apart, get the 4 CD's out, and re-assemble all of it. To test it I used a CD I didn't care about and the changer will not play it and will not spit it back out so I guess the CD player/changer is just dead. (HU 801)

My question is:

Will an aftermarket stereo play nicely with the rest of the car's electronics assuming that the proper wiring harness adapter's are used ?

Apparently the car has some sort of alarm from built in - will that still work?

I'm assuming the steering wheel controls will no longer work but that is no big deal. More concerned with other things I don't even know about being disabled or malfunctioning.
2000 S80 2.9