Yep I heard it again today...I had forgotten about it, heard it the first night I parked it with a full tank. I heard it again with the second fill up...and when I parked it in the garage today after just filling it up, 5 minutes later POP! About as loud as half a firecracker, yeah I jumped. The first time I heard it I thought it was the Bilsteins in the rear because I had just put it back to normal suspension and cut the ignition off. 3 times now, after three fill ups-is no coincidence...Any thoughts? Plastic tank? Straps? Added weight of gas on suspension? Anyone else heard this?