Add me to the list.

I think my "park position" is messed up. The wipers operate fine when continuously wiping, but when they are wiping intermittently, they wipe twice then stop. When they stop, they go all the way down, then back up a few inches. Then after the windshield is completely full of rain, they'll wipe twice again and park in the same spot.

Here's the new park position:

I had to replace the wiper motor on my mothers E39 for that... the park position switch is in the motor. I should have kept the old motor and pulled it apart to see if it was a fixable problem, but we didn't have the time for that and simply threw in the new motor.

This is the same problem I was having. It turned out to be a $20 relay, which was located in the box on the passenger side of the firewall. Give it a shot. I replaced mine almost a year ago and it has been working fine since.