Why does the Audi A4 fuel gauge show inaccurate readings?

I've noticed that the fuel gauge on my Audi A4 often displays inaccurate readings, showing more or less fuel than what is actually in the tank. Is this a common issue and how can it be fixed?

This is a common issue in Audi A4s, and it can often be attributed to a faulty fuel level sensor. It's important to have this issue addressed by a trained mechanic to avoid any potential problems on the road.