Sony Plug and Play XM receiver...
Complete kit includes external "shark fin" antenna, mounting bracket/cradle, 12v power hookup, and cassette player adapter.
I used it in my semi for about a year, works great!
Will post an actuall picture tomorrow when I get home...
Looks like this:
Asking $50. I will accept USPS M.O. or Paypal +3%.
Thanks for looking.
ETA: Price includes shipping