2008 Toyota Highlander Hybrid - Loud Humming Noise
Just purchased a used 2008 HH - about 85000 miles. Seems to work perfectly except there is a very loud hum that sounds that it is coming from the rear. Starts to be noticeable at 30 MPH and gets louder up to about 55, and then isn't as noticeable, perhaps due to normal road noise. Any suggestions as to what this is?