My 89 wagon has air conditioning and there is a place by the fuse panel where a "flap" could be opened but is not a feature available on models w/air cond. I have an 83 242 ready for the bone yard with this feature on it. I enjoy the cold air coming in and I was wondering if these parts are interchangeable. If they are how is access possible? Through the wheel well or by taking apart the fuse pannel plastic thing on the inside?