Once the screen is fitted I could mark out where the wiper spindles go, they start 5mm out from the edge of the screen rubber and 415mm from the adge of the screen post. Its the same for both sides. these holes are at an angle hence not round. I found the best way to get the shape was using the washer from the spindle kit and to get the angle i used the plastic sleeve that goes over the spindle. Also with the screen in its a good time to mark out the heater slots.
Then its screen out and start cutting :)