Subaru Repair: Towing Noise, vibration noise, typical issue

Question
I have a Forester 2ltr 2005 45,000 miles; when I am towing my caravan I occasionally get a rumbling vibration noise. This can occur at any speed between 30 & 60mph often when changing gear. If I ease off on the accelerator it stops & also if I take the car out of gear the noise stops. A garage has checked underneath & can find nothing obviously wrong. Can you please advise what is causing this?

Answer
Dave,

That is a non typical issue and there just is no way I can advise you without experiencing for myself the sensation you are experiencing.

If the problem can be duplicated by  a shop where you live they should be able to figure it out.

If not take it somewhere that knows Subaru.

Justin