My 2010 SRX (91,000 miles) is making a low-pitch squeaking sound going over speed bumps and sometimes, when up and down curbs. It does it in all weather so it's not cold related. Took it to my dealer and they claimed not to hear it which just meant they didn't test drive it because it squeaked as soon as I went over a bump when I left the dealer. I've taken it to another service place and they can hear it but can't find the source. They say everything is tight. Any ideas? What further info can I supply that might help? Thanks.