My girlfriend has been looking for a new car now for awhile. She doesn't want to spend much money (looking for sub $15k) and has seen a few 3 series pop up in the price range. Now my questions- How high of milege do these things get up to before they are complete money pits? Is there anything to really look out for when shopping for them? Finally, what kind of routine service can she expect in this MY and milege rang?

Thank you in advance for any input!
Alex