I have a 2000 conv't and I haven't had this problem. There are those felt covered (or whatever that trunk material is) trim pieces in the trunk (one on each side, one in back by the latch and one that separates the trunk from the conv top area). If that separator one is missing and you have something large in the trunk that protrudes in the conv storage area, the hydraulics will pull that glass right down on it. Make sure that separator piece is installed. Also, if you have kids, they like throwing toys and stuff back behind the seat when the top is up (or, in my case, my wife placed a mop back there cuase she didn't feel like opening tyhe trunk). Then, when you go to put the top down, those items will get caught between the conv top and the rear glass.