Audio Systems: radio reception in Audi, radio chassis, audi cars

Question
I have owned an number of Audis.  I have had the same poor reception in all. I have tried different fixes with no luck, including changing the system. There seem to be different antenna placements with each model. My current Audi is a 97 A6.

Answer
I can see reason for poor reception on all your Audi cars, have you put them along side other cars at the same time and place to compare reception?
Anette well earthed and extended. power if amplified, good connection on radio, radio well earthed, should work. make of car has nothing to do with it. I had a 1987 80 sport, great radio.
p.s.I alway fit a seperate earth to the radio chassis.
peter