I know it's not the same exact thing, but my 2 light in my sound bar in my YJ rattle when I play music too. When I put my hand on it, it stops. I'm going to take mine right out and fab up a new light thing. But you have a nice Jeep, so that would be a horrible option lol. Could it be the bulb inside that's vibrating? Are you positive it's the lense?