overheating issues
First thing to do is check the cluster and coolant temp sensor.
Both the cluster (temp and fuel level mostly) and the coolant temp sensor are high failure items.
You need to buy/ borrow a VAG.com to run the tests on the cluster and compare the gauge to the ECU. Another possibility is you have old style water pump with a plastic impeller in there and it's breaking up.
VAG.com is a diagnostic setup that works on VW/ Audi cars.
Visit Ross-tech for more info, an essential part of your toolkit if you want to work on your own car, or if you want an idea of what ails you before taking it to a shop. Will work on both your Audis.
I have had Audis for over 12 years and it has saved me $$$$.




