Weird sound coming from the back of the car..

Just heard this the other day and it sounds like to me honestly like my mom's air compressor in her van to give air to the tires. Its comming from the passenger side in the rear. My friend says it might be the exhaust hitting on something..Any one knows whats up before i take it in tomorrow

yeah, that def. sounds like an exhaust thing..it's prolly just a hanger, my moms van's exhaust made that sound for a really long time, and then I finally looked under, and it was out of the hanger, rattling around and s***. It's nothing serious, but it causes stress to the piping, but I can pretty much guarantee you that it's something along thos lines with ur exhaust. Also, it could be up against something, vibrating...I dunno, pissing in the wind here.

i'll take a look before i head to the dealer but thanks for the insight