I ordered the "Scion tC Sirius Satellite Radio" kit from an eBay store based out of New England... they are here:
http://stores.ebay.com/SCION-WAREHOU...Q3amesstQQtZkm
I buy all my stuff from there... the install was easy. The parts came with instructions. I got my spoiler and subwoofer there as well. Good business.