I don't like this issue either, but I don't find that I have to get out of the car to do anything about it? I'm fairly average height (around 6' even), and I just reach over the rollbar to push down on the center of the plastic window when the top is about 1/4-1/2 of the way down. This gets rid of the fold in the center, the same as doing the chop...
Either that, or I just have gargantuan ape-like arms, and would be more at home in the trees...