I have done countless searches on here and on the internet and I can not find a set answer. I have a 05' tc and I want to install XM on it. I want to run XM thru my stock radio. Do I really have to go back to the dealer and buy it from them? What exactly do I need? Can I buy the tuner and adapter from Crutchfield? Or should I just go to Trdsparks and get it there? Please help....thanks!!!