Originally Posted by Bonzo

My post may be totally useless for this car, I don't know. But I can tell you that it totally worked on my old Chevy Tahoe. I had a nasty moldy smelling air conditioner, and couldn't figure out how to fix it. One day I read an article by the car guys in the newspaper, and what they said to do totally fixed my problem, 100%. What I did was mix a 20% bleach 80% water solution and then poured it down in front of the windshield. As it turns out, the drain path for water going down in front of the window also rinses through the air conditioner water drain, which is where the smell was coming from.

Again, not sure if the Z is made this way, but it certainly worked on the Tahoe. Might be worth a try. Can't see how it would hurt.