I have a constant (thoughout speed/rpm/idle, range) fluttering noise, almost like air escaping towrards the front passenger side of the engine. its definitely rpm related (increases/decreases depending on rpm). i hear it the most when i stick my head under the front bumper on that side. hard to pinpoint where exactly. Any ideas? i thought maybe exhaust leak or cooling fan clutch, maybe even A/C clutch/Compressor. Its very annoying, louder than my engine and exhaust.