1. On many trucks and SUVs, the rear glass, above the tailgate, can be opened up to provide additional ventilation or a little extra space for that couch you're trying to move. The rear glass hinges are what let the rear glass open and close. The hinges are mounted at the top of the glass and attach to body just below the roof. They are usually made of metal. A hinge bolt allows the hinge to open and close smoothly, just like the hinges on any of the doors in your house. 2. Because rear glass hinges are mounted on the outside of glass, they are exposed to the elements. Metal can start to corrode. You may notice mineral deposits beneath the hinges on rear window glass. That's from water streaking the rust over your windows. If hinge bolt corrodes, hinge can either become stiff or loose. It might be hard to open rear window or keep it open. A loose hinge might eventually give way and let rear glass fall off, which could easily break it. In that case, you need to replace it. 3. This Rear Window Liftgate Glass Hinge Fits the Following Vehicles: 2008 2012 Ford Escape, 2008 2011 Mercury Mariner, 2008 2011 Mazda Tribute. 4. Customers can find the product you need accurately according to the OE number. OE part number: Left 8L8Z 78420A68 D, 8L8Z78420A68D; Right 8L8Z 78420A68 C, 8L8Z78420A68C; 924 123.