I found one of the biggest sources of a rattle in my 05 RL, it occurs on the highway at high speads and sounds like a distant baby rattle. You can also sort of simulate it by pounding on the top of the dash a little with your fist just above the glovebox. then while you are still lightly pounding on the dash and faintly hearing the rattle. touch the enter nob in the center of the console and the rattle goes away. I am road testing somemore to verify!!!