I ran an ISPRO fuel guage into the cubby hole of my Ram. I used High pressure rubber hose as per not recommended but it's only 15 psi and I feel stainless braided-w-AN fittings is overkill. Anyway I've had a rattling that I could not find. It turned out to be the fuel guage even though the needle wouldn't vibrate it was the culprit. In the engine compartment I put a very small, in-line fuel filter in the hose and the rattle is gone. Thought I'd pass it on as an easy/cheap fix.