Audi Repair: 1998 audi a4 Quattro 2.8L 100k miles, audi a4 quattro, 1998 audi a4 quattro

Question
I just bought this car knowing it needed a new transmission. I took it to a transmission shop who told me they rebuilt the transmission.  

When I drive the car in stop and go traffic I hear a loud clunking noise.  I think its the transmission but they told me its the AWD system.  It doesnt happen all the time. It only happens in stop and go traffic. Like if I am stopped and give it gas it will give me a loud clunking noise.  I hear it from a few different places, front and rear.  Im not sure what it is.

Any ideas what it could be?  Do you think its transmission related? What part of the AWD system would it be?  Is there a way to disable the AWD to test?

Answer
This could be a loose driveshaft, or a CV joint, or actually internal to the transmission.  It could also be in the differential, or it could be a transmission mount which is bad, the only way is to get a trustworthy shop to evaluate and diagnose properly.
There is no way to disable the AWD on an Audi quattro, so the system has to be evaluated in it's entirity.  But this can be done on a lift.  let me know,  Jan