Thanks for the replies!!
For those that have replaced the factory head unit with a store bought one, how does it sound with the stock speakers? any improvement or degrade in the sound? i'm not interested in the whole screen on the radio, that would just make me want to watch it instead of drive.
i might just go with a splitter that will let me hook up my ipod and satellite radio to it. Sirius sent me antenna adapter but i don't think it uses the standard input connection (the little headphone looking jack) so it would only work with their unit.