Here's the original:
As I said, the vertical scale variation seems to me to be a bit exaggerated - but that's what they published.
Note the suction peak at the header rail of the windscreen, but how that occurs over only a small area. If we were shade the low pressure area of the graph across the roof and rear hatch, we end up with the majority of lift happening between positions 30 and 45.
You can be pretty confident the fairly large rear spoiler added to the turbo (and later 944) versions increased the hatch pressures quite a lot.
The full graph is also interesting in that it gives us front and rear undercar pressures. (I edited these out inthe 'quiz' graph.) So position 1 is slightly less than atmospheric pressure (ie under front bumper) and positions 46-50 are all at wake pressure.
The odd front pressures that confused people are apparently just the result of the bumper/intake shape.