Great post !
I'm so happy I found this site and post. I bought the replacement washer pump from a local part dealer for $21 that fits exactly into the original bmw electrical wiring. I'd bought one from autozone with a modified wiring so didn't like it.
For those who need this info: my car didn't have any leak, the tank was full and I was able to recycle the fluid during the pump replacement process. I didn't have to change the grommet/filter thingy either.