GAH! I'm POSITIVE this episode exists!!!
So I remember watching a very special Magic School Bus episode on my local PBS station...special because at the very end, we got a behind the scenes look at the show. They explained how the animation was done in South Korea, Lily Tomlin's lines were recorded in the US, and the kids did their voice acting in Canada. I was riveted because it turns out the "kids" were actually teenagers with some of them resembling their cartoon characters. The voice behind Dorothy Ann for one, I think, looked sort of like the cartoon DA.
I think this was part of a Christmas special. I've been Googling like mad, trying to find the episode title or the episode itself. Does anyone know what I'm talking about? ? ?