What causes a shaking or vibrating feeling in an Audi 80 at high speeds?

I have noticed a shaking or vibrating feeling when driving my Audi 80 at high speeds, especially on the highway. What could be the cause of this and how can it be fixed?

The most likely cause of this shaking or vibrating feeling is an issue with your tires. They may be unbalanced or worn, which can cause a bumpy ride at high speeds. It's recommended to bring your Audi 80 to a trusted mechanic or tire shop to have them properly inspected and potentially replaced.