loud whistle from back passenger side on 2001 Jeep Cherokee

i have a 2001 jeep cherokee. Does anyone know what would be the cause of a loud whistle noise coming from the back passenger wheel area. It starts when the car is moving and is louder with higher speed.

Asked by for the 2001 Jeep Cherokee
Inspect both of the plastic Wheel Well Liners in the rear wheel wells and make sure all the fasteners are in place. Also, if you have a luggage rack, the placement of the cross bars can create an annoying wind noise . Lastly, iif the antenna mast is not the original, if should also be suspect as sound travels.