First the good news. If your transmission thumps when you're coasting downhill at Interstate speeds, you don't have to pay $9000 to have an Audi dealer replace the transmission.

For a little over $1500, the Imported Car Center in Williston, VT, 802 878 3391, removed the transmission, replaced the torque converter with a rebuilt unit, and reinstalled the transmission. I recommend them highly. The thump is gone.

The bad news. I still have about a 100 RPM hunt when coasting downhill at Interstate speeds. Does anyone know how to fix this problem?

I believe that this is a programming error from VW Audi.. this hill detection option that i hear about makes me think if that is the hunting issue. I dont think its mechanical. I wonder if vag com can fix this or the giac tip chip claims to eliminate the hunting in all audis and vw's.. I am waiting to get my t. converter fixed before i get any chips.. i dont want audi throwing it in my face when the tranny that they messed up breaks.