Hello everyone! I've got a question about my new 2003 330i. If I'm sitting in the car waiting for my kid or something, I often like to play the radio or a CD. I've had problems with previous cars (non-BMWs) where the battery died if I used the radio without the engine running (and alternator charging the battery). So I'm wondering if it's safe to run the 330's radio without the engine running, and, if so, how long I can do it without starting to drain the battery too much. Also, if I should run the engine while sitting there waiting (so the alternator keeps the battery charged), is that doing any damage to the engine, since the car isn't moving? How long can the engine idle without the car moving before it starts being a problem?
I guess I'm asking, "Which is worse for the car: running the radio off the battery while the engine's off -or- letting the engine idle for (10, 30, 60, etc.) minutes?
Thanks in advance!