Hi, thanks for that. I used to do it that way, but like I said, it won't quite do it. The rubber will still have enough flexibility to ride over rubber window seals. The idea of sawing into channel is so the metal can be bent up and towards the CORNERS of the rubber thus preventing it from leaving a line all round frame.
It still requires a good technique of course.

i dog eared my squegee 2 months ago still wipe out of habit but it does make a difference
i,ll never stop wiping as i wipe pvc round the windows after i applicate the window

but for shops etc its the business 1 cloth can last 2 hrs ..i,d usually use 7/8 in that time 

Yes, though Iv'e tried a slight angle but it does'nt seem to make any difference.

Never bothered with dogearing, I just nip the corner off the rubber so it fits tight to the edge of the glass and edge of the rubber seal. It kinda fits just like a jigsaw and leaves a good job.

Wish I could think of another way without weakening it too. I still do it though because it's so effective.
If anyone has any ideas it would be appreciated.
Wagga.