Why is it that when the rear windows are down and front windows up in my 2006 jeep liberty the air pressure changes and makes a heck of a thumping noise is this common?

Answer 1

You are building up air pressure in the rear compartment and when it gets too high it puffs out the front windows momentarily interrupting and reversing the air flow through the windows. Crack the rear ones slightly to allow the air to escape and it will stop. It has to do with the aerodynamics of the vehicle, on yours air is directed into the windows very efficiently but with little relief so it builds up and breaks through the flow.You can also remedy this with the front window air deflectors that you can buy at the auto parts stores.