sounds like your vent is plugged up or broken, so when you drive you create a vacuum and the fuel tank is being pulled in, thus the banging I just had a car with this issue, and I had to pull the tank out of the car and had to the show the customer before he would believe me, but seeing IS believing as they say.
When you shut off the engine the vacuum decays and thus the tank reverses its process. Try driving your car with the fuel cap off and see if the noise goes away. That will prove it!
(also)- small leak in the tank
and finally try changing the gas cap itself
let me know
thanks
~Dave
RockAuto Parts Catalog these folks are the best around for auto parts and believe me when i say you get your parts (if needed) before they say they will be there been there my friend.
if this does not work let me know and we will get this fixed i have had every problem with these luminas you can ever think of this is a fact lol and some are and can be nightmares but great vehicles no matter what anybody tells you i have owned them and worked on these for years now and this is 2014 so take it from there i have owned a 1999,98,97
~Dave