I have desperately been trying to figure out a rear end rattle in my ‘07 LX470 for months. It has 154k miles on it. I have removed the spare tire completely. I have wrapped clamps around the cats like so many posts say. I have touched every part I can reach and nothing is loose. The heat shields are firmly attached. The noise happens after the vehicle has been driven for more than 10 minutes and most often at low speeds on rough roads. It literally sounds like something is about to fall off the vehicle. Please help!!