When I bought the car, the wiper motors were working intermittently. By the 3rd day of ownership, they quit working all together. I could hear the motor attempting to turn, and the fuse and electrical connections were fine. After some research I found a how to piece on how to attempt greasing and oiling the wiper motor before buying a new one. This link below from Tom's BMW 2002 Repair details step by step on how to pull the motor, grease the bearing and oil the gear. It's a pretty easy process, but be careful to pull the motor straight out when taking the motor apart. See the link below. Pay special attention that your wipers are parked correctly before pulling them off the spindles.

This step by step worked great and the wipers are working fine now.

Please note that I do not have pictures of my car in this process as I am documenting this from the past to present. The next project I will document (alternator issues) will have pictures with step by step.

http://laudeman.com/bmw_wiper.html