I don't remember the reason, but I didn't have much luck with the rolls of window setting tape. they just kinda broke down easily as I recall. I did use it to hold the edges on the quarter glass trim, but on the side glass I re-used the orignal rubber. I think I might have put the channel in a vise and pinched it just a smidge tighter though. OR opened it a little. I think the after market glass was just a fuzz thinner or it was wider. lol Wasn't that long ago & I am already forgetting some of those details. I usually bounced that stuff off you guys so I probably have a thread on it somewhere.