You can benefit from my stupidity. My XM Sat tuner quit working while on a trip west a few years ago. I stopped at a dealer, purchased a replacement tuner, and went on my way, installing it later. Installed it, and still no Sat. reception. Turned out it was my head unit. Never got around to returning the tuner (that's the stupid part). $400 new - yours for $150 + shipping. NEVER USED.