Deceleration vibration

Just taken the S3 for 60 mile round trip for a job interview and heard and felt the most annoyig vibration Ive ever experienced in a car. Now the car has recently been returned to me from the Audi bodyshop and it certainly wasnt there when it was delivered to them. In any gear when decelerating....foot off the throttle, there is a real bad vibration that can be felt throught the whole car and a loud rumbling noise. Now if you knock it out of gear the noise stops straight away and when put back in gear it returns until the car is slow enough and it stops. Now if I put my foot back on the throttle slightly the vibraton stops......its only when there is no throttle input......any ideas. Im waiting for the garage to get back to me as I dont really wanna drive her if its a serious issue.....ie gearbox.

Is it just coincidence that its been in the oven at the bodyshop??? Something dried out possibly.

Booked in for 0900 tomorrow so hopefully they'll be able to track down the vibration.

On a similar note when I was in the RAF we had a jet that had a serious airframe vibration and after roughly 3 months of various test and changing almost everything in the flying control system....Bae requested it to be scrapped. 7 years down the line and that same jet is still in pieces in the hangar waiting to get rebuilt as they changed their minds. Oh well.

Checked and all secure. I also haven't fitted spacers as I know thro other threads this has caused vibration. Ive felt vibrations from items failing like driveshafts but this feels and sounds awful......so much I dont really wanna drive her tomorrow to the garage......see what happens.

Right then, diagnosis is.........top-hat section of the prop shaft has completely split........apparently. The master tech guy said this is the 3rd occassion on an A3 he has seen in 2 weeks with the same fault.

Any ideas what would cause this and how easy is it to replace........all under the warranty so phew!!! Would this cause any other problems such as to the Haldex system??

No timescales at the mo from the garage so I will just enjoy the A5 2.0 TFSI Black Edition they gave me. Nice car but prefer the S3.