No, your post was not confusing... I just did not read yours correctly. I thought that *SHE* was the one driving the 82 300D... oops!!
Anyway, I did get a tuner for the radio. Don't buy the tuner by itself. It's about $249. If you buy the universal kit (which includes this same tuner and other unneeded accessories), it's $100 cheaper. See:
http://www.crutchfield.com/cgi-bin/S-3shM3dAeldg/ProdView.asp?s=0&cc=01&c=3&g=79800&I=500XMAT200
I've had XM for a few weeks now. It's cool... not bad. I got a magnet mount antenna and run the wires around the rear window channel then into the trunk.
See:
http://www.crutchfield.com/cgi-bin/S-3shM3dAeldg/ProdView.asp?s=0&cc=01&c=3&g=102500&I=209XM3++++
I also have an extra one I'm willing to sell. It's:
http://www.crutchfield.com/cgi-bin/S-3shM3dAeldg/ProdView.asp?s=0&cc=01&c=3&g=102500&I=209XM11+++