here's a couple of pics of mine, tho the car is in the sun so made it tricky.... bonnet centre is about 45mm from screen (perpendicular)
looks like about 5mm from nut to bonnet
Nsx wiper clearance by NSX Jon, on Flickr
and the arm clears the bonnet... you can see the gouge from previous owners not putting the arm on squarely....
Nsx wiper clearance by NSX Jon, on Flickr
i can take some more pix at dusk, when i can see what i'm looking at, if need be
hope that helps