Thunk from rear going over potholes or bumps

[Slabber]

Every time I go over a pothole or a bump in the road I hear/sense a 'thunk' from behind me. My garage have given the suspension a thorough going over and can't find anything wrong. The exhaust seems to be firmly in place. Anything else they could check?

[ainarssems]

Rear diff bushes and check if the spare wheel is secured in the boot or any other loose items in boot / spare wheel well.

[Slabber]

Thanks for that! Spare tyre is definitely secure but rear diff bushes sounds like something that may not have been checked.

[Slabber]

Okay, my garage (Audi independent specialist) have now given my car a thorough inspection and can't find anything wrong with the suspension, nor with anything else that might be causing the 'thunk' from the rear. They can hear the thunk though, which is something I suppose. I'm now considering having some rear suspension parts replaced on a speculative basis. Grateful for suggestions as to what to start with!