cd strangeness & stalling issue

[Brice Warnick]

It could be the decay of the magnetic field in the A/C clutch.
This will cause missfires and affect the radio and the A/C control head.
It missfires when the A/C clutch disengages.
Does this happen when you have your A/C on only? 
There is a an Audi Technical Service Bulletin on this requiring a Zenner
diode kit 443 298 008 and an updated compressor clutch relay 443 919
578H. See if you already have either.
The relay is under the footwell.
Rod at TPC has the new relay in stock and the Zenner kit is dealer only
which you can get from Clair for around $86.00