So... This occurred just last week and I figured it may be due to the cold but we had a warm day yesterday and it didn't let up. It sounds like its coming from just in front of the drives side firewall. Oddly enough, it doesn't get louder as you move down to the floor, but rather is louder up top. It sounds like a top air soft gun against a tin roof.
https://mail.google.com/mail/?ui=2&ik=a44928ecc4&view=att&th=12ce20050568e2a8&attid=0.1&disp=attd&realattid=1355055729566810112-1&zwI apologize for it being at night and you cant see anything, but the hood is popped and its right over whatever coolant holder is in that corner closest to the driver. You can hear it best at 6 and 9 seconds I think. And its not the usual engine lope I'm talking about. you can hear it driving, through all rpms (sometimes the engine is louder, like at 6k) BUT whenever you come to a light and put it into neutral, and it hovers at 750, the noise is gone. However it still chatters like crazy when driving at say a constant 2k. I couldn't get that noise to show up on my phone, but my girlfriend even noticed it today. The car is bone stock (except for 'lil chromies but i HIGHLY doubt that they are the issue

)and has about 33k miles on it. I bought it used at 27, and I haven't done any major fluid changes other than oil. Could this be it?