Just this month, my S70 decided to start making this really loud rattly noise. It only does it at idle, and its like a metal-y rattle noise. It comes from under the car. Its super annoying and I want to fix it really bad. Does anyone know what it might be?

I'll try to get a video up soon if it helps.

 

Exhaust... either a heat shield or a rusted pipe hanger. Heat shield isn't a difficult thing to fix... usually you just reattach it somehow.