What is causing the shaking in my Audi 80?

I've noticed that my Audi 80 starts shaking when I reach high speeds on the highway. What could be causing this? Is it a serious issue?

The most common cause of shaking in a car is an unbalanced wheel. You should get your wheels balanced and aligned by a mechanic to solve this issue.

Another possible cause could be worn out suspension components. I would recommend getting your suspension checked by a professional to determine if this is the issue.