Why does my Audi 80 sometimes make a rattling noise when shifting gears?

I've noticed that while driving my Audi 80, there is sometimes a rattling noise when shifting gears. It doesn't happen all the time, but when it does, it's quite noticeable. Any ideas what could be causing this?

It's most likely due to a worn or loose transmission mount. Over time, the mount can become worn out or the bolts may come loose, causing the transmission to move around and create the rattling noise. I would suggest having this checked by a mechanic.