What is making oily water stains on back of my vehicle? on 2002 Buick Rendezvous

I keep seeing round, oily water spots on the bumper and back of my vehicle. Can you tell me what is causing this?

by in Potwin, KS on August 28, 2013
1 answer
ANSWER by , August 28, 2013
You have a leak! Engine oil or transmission fluid most likely.