I was talking to a fellow who does convertible top Restorations recently and he told me every time you put your convertible top down you should unzip the rear window pane. Could this possibly be true? It is hard as woodpecker lips to get that zipper unzipped and rezipped. The man I spoke with said that if you don’t unzip the top before you fold the convertible top down you put undue pressure on the folding glass. The owner’s manual does not address this issue. Does anyone have any practical experience in this regard?
Thanks, Tim
I have never unzipped the folding glass window on my tops. Never. Agree they are super difficult to zip and unzip. If it leads to replacing it more often, so be it. But after nearly a decade with mine unzipped and folded and stowed away- no issues.
My 2 cents here. The owners manual does address that the window can either be unzipped and folded down or left zipped up.
It must NEVER hang on the assist strip attached to the number 4 bow alone however.
A bit of ‘Door Ease’, sold by Ford or other approved lubricant could also be used on the zipper to assist in operation.
I personally have left the window zipped up just for convenience.
One other item, if lowering the top with the window unzipped, it must be stowed flat against the well compartment and NOT resting
on the rear seat back.
Thanks for the info guys
Some car show folk would NEVER put the top down on a convertible, PERIOD.
I have heard that about the back window as well, but never followed it. I took care not to put the top down when it was dirty though.
Here’s the exact words from the 70 manual. Chris raises another convertible top question - how do you clean it? I have been vacuuming mine because when you wash it, you dump all that water down into rust prone areas of the car. And then here in humid KC, it could be days before everything is dry enough to put the top down.
I used to religiously unzip and lay down the plastic windows in my convertibles that had those, especially if it was going to be lowered below 50F for some reason.
My '70 Cougar was actually supposed to have been built with the plastic window used for export and that’s what it has now. However, I don’t unzip this one. I just take care to make sure it has a clean bend without any kinks as it begins to fold.
I don’t think my R Code got wet after 1987. Once it was “done”, I’d just use Speed Shine & detailing clay as req. For the top, I’d use a duster, damp cloth, dry cloth. Used to love driving w/the rear window zipped out. A bit of bar soap rubbed on one of the zipper tracks makes the action smooth as silk.
Then what’s the point of owning a convertible 
I have usually unzipped the rear window before putting the top down since I put on a new top in 2008. Before that I had the originl top that was in fair condition and didn’t worry about it. Normally I unzip the rear window in the spring and zip it back up when it gets too cool to drive with the top down in the fall even with the heat on, except when away overnight with the cougar and parked outside.
Steve
When we (WCCC) did the video of replacing the top on my 71 I went with a canvas top and not the vinyl that was original. The guy in the video, Steve made sure that I understood that I had to unzip the back window EVERY time I put it down. He was one of the few FORD factory authorized warranty top replacement guys here in the Portland area in the late 60’s and 70’s. He told over and over again with a replacement top unzip the window. Part of the reason he said is the canvas top is thicker than the vinyl and folds differently and will not set as deep in the well. I used to put the original top down with the window zipped as the owners manual said I could, but the first time I forgot with the new top the window caught the seat back and I thought I broke it. My grandson just replaced the top on his 83 Mustang and we were again told unzip it. After the 30 day wait period we started to put the top down and even unzipping the back window we could hardly get it to go into the well. We’ll go back for some final adjustments and maybe have a better discussion on why unzipping the window is that important. Could it be that it’s just a rule so the installer is not liable for the glass?