One problem related to wiper has been reported for the 2004 BMW M3. The most recently reported issues are listed below.
Got into my car in the afternoon and noticed the rear view mirror was distorted. After inspecting, realized that the liquid had separated behind mirror. Had to run an errand. Started driving and then heard a loud "pop" noise. Looked at mirror and the liquid was very visible moving behind glass. Got to my destination and noticed fluid all over seat and center console. Immediately wiped up and it had already damaged center console in several places. Got it off seat before it damaged the leather. Had to wrap towel around mirror to catch the rest of the fluid leaking out of the bottom. This fluid was extremely caustic and did damage to console in less than a minute. I'm glad I was in car when it happened, I am sure the damage from the fluid would of been a lot worse!.