Hello everyone I have a 02 v6 mustang 5 speed with 146000 miles on it, today I noticed a loud helicopter like noise coming from the bottom of the car when I let off the gas 50 mph+ or sometimes when Im accelerating, it sounds like something is flapping around the noise comes and goes randomly when im driving, my tranny shifts smooth my engine runs strong , oh and also I cant feel any type of vibration ,car runs perfectly fine but the noise is there and its annoying!