So Mark B. Magee says:
> 
> Sorry Volks, new to me Vanagon '87 GL and I can't for the life of me 
> figure how to activate the rear hatch wiper. I feel foolish, but I'd 
> rather be able to turn the rear wiper on than live with my pride!
> Regards

Tap the wiper arm control forward (not up or down) to engage the rear
wiper.  To disengage, tap it forward lightly again.  Disengaging is
kind of tricky.  You have to hit it just right or it won't stop.  You
need to tap it just at the end of the initial sweep and then after the
return sweep it will stop.   

Steven