I had the same prob on my 04 i was going to have them cleaned but took them off instead very easy to do.esp now that it has warmed up.Park it in the sun after a while go and peel them off they come off very easily lil sticky stuff left behind but adhesive,bug tar,wax remover stuff took care of what was left then use a lil compound and wax it.
took about 20 min for the whole job