I own a 2002 rx300, the present mileage is approx 15500. Since purchased new this vehicle has had a rattle/tapping noise from the cargo area when driving on rough roads or irregular seams in pavement. The dealer has not been of any help. I have removed the cargo cover, spare tire, tools and everything else. Rear seats up, rear seats down, seat belts buckled. I have installed rubber pads under license plate. Can anyone HELP !! :(