ok, so today i was checking some fluids. yanked the auto trans stick on my 2010 xrs, and ut-oh, the top of the fluid tube if "caked" with dirt !! car has 15273 hwy miles on it since mid dec 2009. the top of the fluid tube seems to be right inline with the airflow that comes through at speed and/or when the fans are on. odd part is, the dipstick itself has a lip on it that covers the edge of the fluid tube by a small amount, so the dirt is actually blowing up under the bottom side of the dipstick and then the dirt collects at the top flared section of the tube. the dipstick did have a few specs of dirt under the o-ring. in any case i think this issue has not been accounted for by the engineers. two issues, dirt can migrate into the tube, and, when you yank the dipstick out dirt falls in. my remedy for now is to place some sort of cover over the top of the dipstick.
also, the 2nd dip in to check the oil the dipstick came out with some odd looking debris on the stick. perhaps some assembly crud, but nonetheless crud that really should not be there....