Static on my Sirius Radio?

So I bought a Sirius radio yesterday and it's hooked in and working. Problem is I get quite a bit of static through the speakers. I've already found an optimal station to play through. Is there anything else that could cause the static? Should I be using the extended FM Transmitter that came with it? Should I continue to look for alternative stations to play through? Should I just get in professionally installed and not deal with it? Any help would be appreciated.