help what is causing this sound 2001 audi a4 1.8 wagon
 

I am hoping you can help. I went to drive my audi and when I backed up
I heard a thumping sound. I not sure how to attached a file I think I did.
It thumps going
forward or back and even in park. It sounds like it is coming from the back end.

I have no clue what this is. Car is sitting not sure if I should drive it. It has 160,000 miles
auto I love her.
https://clyp.it/0trd13kpI

It makes sound in park, drive, reverse, sitting or moving


any insight would be so appreciated.
It happens in all gears moving and sitting.