yeah, it's not just the 3 series. many issues with the 5's also.
also, it's not a good idea to let your tank get below 1/8 - 1/4 tank. having a CF pump get a hold of air will do them in.
not sure i understand the theory, but it seems some people run their tanks to empty when the gas prices spike.

 

Yep, it's just as easy to run on the top half of the tank, as it is the bottom........ cheaper to fill up, tooooo!

 

Sorry to hear that. The first accessory I bought was a locking fuel cap. Was always worried that during a huricane someone may try to siphon gas. Your case brings up another good reason to have one.