How to troubleshoot abnormal vibrations in my Audi 80?

I have been experiencing unusual vibrations in my Audi 80 while driving, especially at highway speeds. The car has also been idling rough. Any recommendations on how to diagnose and fix this issue?

Check if the tires are properly balanced and aligned. Additionally, inspect the suspension components for any wear or damage that could be causing the vibrations.

It could also be an issue with the engine or transmission mounts. Have a mechanic check for any worn or broken mounts and replace if necessary.