Why does my Audi A3's engine make a rattling noise at high speeds?

I have noticed that when I am driving at high speeds, my Audi A3's engine starts to make a rattling noise. It seems to be only happening at high speeds and goes away when I slow down. What could be causing this issue?

Based on your description, it sounds like you may have a loose exhaust heat shield. This is a common issue with Audi A3's and can be easily fixed by tightening or replacing the heat shield.