Originally Posted by alexwhittemore
The USB port and lighter socket turn off with the car, so nothing is going to drain the battery while you're gone. That said, your options all either use the lighter socket or require occasional charging which is dumb.
Other than that, you could opt for something like a mobridge/dennon gateway/parrot MKi series.
Those options you mentioned seem way out of reasonable price range. And also I don't have iDrive. I may be stuck with the occasional charging products, since I'm sick of buying a new AUX cable every 2 months from it getting crushed by my armrest.
Any of those occasional charging products you recommend? Or are there any that could charge from the USB port?