Hi, total newbie here... apologies, but gratitude for your patience and assistance.

I'm looking to buy a 330xi -- my first car purchase ever. Audio is very important to me, but I know nothing about hooking anything up or anything like that. I have some really elementary questions and everyone here knows a lot more than I do, but I would appreciate any clear and explanatory answers.

Ideally, I would like to have NAV, satellite radio, and iPod functionality. So here are my questions:

1. How many of these can I have at once, at least coming out of the dealer? One dealer I spoke to said I can't get Nav and Sirius at the same time. Is that true?

2. BMWs "come" with Sirius, right? What exactly does this mean, and if I prefer XM, how would I go about getting that instead?

3. If I were to want to get all three of these options, somehow, or get a package different than what the dealer offers, what is the best approach for doing so?

Thanks again. I am totally new at both buying cars and expert audio stuff, so I am grateful for any answers.