I have one and I'm almost afraid to use it. When I bought the truck this past spring, I tried it and it barely opened all the way. You could hear it strain. I blew out the track clean and sprayed some WD. It still had somewhat of a hard time. I clean it out again to be sure and sprayed white lithuim grease on the cable and track. Besides the interior smelling a little, it's a little better but still not to my liking. I'm not sure how to completly take it apart for a total lube job