I put an AuxMod basic in my wife's 3 a couple of months ago to replace a high end FM transmitter. I'd been on the waiting list for
ages and it was
well worth the wait. The install took all of about 45 minutes (and that's being
really careful) and it sounded
much better than the FM transmitter.
As for charging the iPod from the car while using an AuxMod, good luck. You
may find that as soon as you connect the iPod to the AuxMod and car power of any kind, you get either that squealing or a buzz from a ground loop. This isn't a flaw in the AuxMod at all, but rather a side effect of connecting to car power. If you try it and get the noise, you might try using a
ground loop isolator from Radio Shack.
I say just run the iPod on its battery if you can. That's what I do.