911 wind****eld wipers?

My wife has an '84 911.  The driver's-side wiper has always been a disaster

-- it's bowed in the middle so there's a swath about 4" wide (naturally 
directly in the line of sight) that the wiper completely misses.  It's 
horrific trying to drive in snow in this thing.

She says changing out the wiper does no good, because within a week the
new 
one is bowed too.  The wiper rest position is to the left, and it hangs
off 
the curved part of the wind****eld on the left side.  Sitting against that 
curved wind****eld quickly bows any wiper you put on it.

I can't believe this is the way it's "supposed" to work, or ****sche would 
have been sued a hundred times over by people who couldn't see and
crashed.  
There MUST be some way to make this thing work right.  Any suggestions??

Thanks!
Gary