embarrasing

I Have A Disatser On My Hands My Car Is Smokey Waaayyyy To Much After About 2 ,3 Days After Washing The Car The Back Off Car Is Covered In Soot And Oil And Can't See The Number Plate Our Out Back Window, Any 1 Had This Problem And Got A Clue Wot Hell It Is?? Got Car Booked In Next Week, Car Is...