'07 squeaking noise

My 2007 is making a squeaking noise when driving over any rough road surface (ie: speed bumps, grates, dip in road, etc.). Seems to be coming from front drivers side. Took it to Toyota but those guys said it was my garage door opener rattling around in the glove box until I took them on a test drive...only then did the mechanic hear it. I said it was a squeak, squeak not a rattle rattle He doesn't really know what it is but says there is a service bulletin for replacing a motor mount gasket? I have looked and can't find anything about this. Has anyone has this problem or have any suggestions? Car only has 6K miles on it. Thanks so much.