I had a wierd thing happen the other day.....we went on a 300 mile trip, a/c blowing the whole time - when we got to our destination and started unloading our two baby boys, we noticed little black spots on their clothes and even on their faces. I looked around more and noticed black spots on the upholstry too. It was diesel soot - looked like copier toner. Question is, how did it get there? Didn't happen on the way home though - strange.