Picked up a yellow r the other night and the previous owner told me it was wired for a disc changer in the back. I know if I go oem I'm going to be paying way too much, is it possible to wire a non - oem changer back there without going through all the wires?

Alpine made the changers for Volvo.
Try to find an alpine changer and it should just plug and play.

I agree with Tech. Check your player, and whatever cd-changer you put at the back, need to match the same system of the one in front. When this is done, it should be as easy as plug and play.

Sometimes, and this is only sometimes, even the same make cannot be plugged and play - one experience I had with my previous car was with Sony systems. My brother got me a used Sony CD Changer and I decided to test it out, since my player was also a Sony. When we plugged it in, the unit failed to recognise the CD Changer as a 'Source' of media. Though the options for it was available. When we tried the Changer on my brother's Integra, it worked fine! Perpexing. :(

BTW, put up some pics of your YELLOW R in the Garage...
:)