On my Eurovan (or T4 or Tranny <-which by the way is Colonial
slang for transmission)8-) I have a similar problem with the
wiper blades skirting or skipping on the very top of their
stroke. I've learned to live with it by driving in the
rain only when I have to....or by keeping my speed down
to 15 mph when I do have to drive in the rain!  ;-)

Actually, where the blades do skip is at the very top of the windshield,
so it doesn't bother me that much...

Ric