My gas cap door latch rattles as well

 

I used to get the rattle in the gas hatch latch a lot. I'd pop the hatch and close it again and that would fix it ... for a while. I've stopped having that rattle but I don't know why it stopped.

 

My gas door button started to rattle on my 2017 ultra last summer. Went crazy hearing it! I replaced it with a kuryakyn when the dealer said they all start doing it at some point. No more rattle….

 

I shot some clear grease in mine and it worked

 

My 2015 RGS has a rattle from the same area since it was new. I tracked it down to the chrome horse shoe shaped trim around the ignition switch, still rattles, drives me crazy, one day I'll get around to fixing it.