Anyone have a humming sound that varies in pitch with vehicle speed, but not engine speed? I usually can hear it start at around 25 mph up until about 50 mph. It's not at all related to engine RPM speed. I'm sure it's something with the drivetrain, but I'm not vehicle savvy enough to know for sure. I couldn't get a service appointment for several weeks, so I'm hoping it's nothing too major, as I need to drive about 1700 miles this week... What do you all think?