I have a persistent rattle in the dome of my 2007 F-150 Crew Cab. It's near the dome light and at rear of the sun roof. When I apply slight pressure to the lens of the dome light, pushing the whole roof liner up just slightly the rattle stops otherwise it's constant. The ford Technician at the local dealership removed the dome light lens and probed around a little but couldn't see anthing that would cause a rattle. Any ideas?