Originally Posted by Some Guy From NY
Does it sound like it is coming from the engine bay? I have a 12/11 build and I had an intermittent rattle coming from the passenger side. After reading the forums I saw it was mentioned that the coolant reservoir tank would rattle. There is an AC line which runs directly under the coolant reservoir..Some members suggested folding a sponge and wedging it under the coolant reservoir on top of the AC line - What I did was get a section of pipe insulation and wrapped it around the AC line beneath the coolant reservoir and I have not heard a rattle from that area since.
Try it with the sponge and see if it works!
Rattle solved! See here for easier future reference by others.