My 2500 came with the factory rear and sliding door frameless fixed windows. I wish to add 3 more windows. I like the look of the frameless factory windows and CLR sells a similar looking window with a bottom half that opens outward for ventilation. Motion windows also sells windows that slide open but don't match the appearance of the factory windows. Some posts have stated that the Motion Windows are of superior construction. I know the CLR windows cost more....any input appreciated. I will be using my van for camping so ventilation is important. I will be taking my van to either Motion Windows or van conversions in Oregon for the install. Thanks in advance.>