The 4 disc player in my '99 s80 no longer works. I found an HU-801 radio for sale on eBay. Can anyone tell me if the radio can be replaced with one from another vehicle? If so, what is the process of changing one out for the other? It seems pretty straight forward from an installation point of view.

it can be done, but you're missing 1 speaker i believe in the center of the console that comes with the hu 801. you're also going to have to reprogram the car at the dealer to read the new hu as its own. Not sure of the cost. I believe the speakers are the same in general though.