So two nights ago my passenger side-view mirror was stolen while my car was in the driveway of my house. I can only assume that someone knew what the car and part was and needed a mirror themselves, or it was just some kids. It seems to be a recurring problem, as my neighborhood friend with a 96 white m3 had his window smashed for a gps and ipod, and this is in a nice bethesda neighborhood.
Anyway, my question is this, what is the best way for me to get another one? Online? the dealer? used? let me know if you have any advice

Look on here for the cheapest, they will likely be used. If you want you can order them through the dealer, but you will have to pay a lot more, and it will come unpainted I bet, so you'll have to pay for paint too.

This forum is your best bet, or other online sites like www.pelicanparts.com or www.bavauto.com if they have them.

We had a string of minor thefts at night in my quiet, extremely safe Fairfax neighborhood, as well. I chalked it up to bored kids, as CDs were thrown out of cars, etc. The only thing of real value that I heard about being stolen was a neighbor's rather extensive (and expensive), jewelry collection. No fun.

Anyway, good luck to you. FWIW, you can buy surveillance equipment fairly cheap nowadays, and get those MFers on camera if they try to come back. I considered doing that but for us, it wasn't worth it--someone did go in my E30, but they only looked around, I think.

Of course, you'll need some kind of infrared camera to see the people at night, but if you're really motivated, it's definitely a [somewhat] viable option. :D