The only difference is the vents in them. I can't remember off the top of my head exactly what year they switched. But the older Jeep hard tops had air vents in them on the back corners, and the Jeep itself had no vent in the tail gate. Then the newer Jeeps had vents in the tailgate and the newer hard tops had no vents in them. I have a 99' with no vent in the tailgate, with I believe a 04' hardtop on it, and it does not have vents either. Sometimes my doors need an extra push to get them all the way closed because I don't have either air vent. Correct me if I have this backwards but I believe this is true. I've also heard rumors which I don't know are true. But I've heard people in my situation blowing there back windows out if they shut both doors really hard at the same time because of the air pressure in the cab not being able to be released. I don't know if that's true or not.... But like I said if my door doesn't shut all the way I just push it in a bit after closing it, or I leave my driver side window cracked a bit and it makes it easier for them to shut.