I fitted a hood deflector this weekend and when I popped the hood up there was a film of what looked like grease/ oil on the tops of both of the wheel arches - I havent plugged the holes there yet as mentioned in another thread but this stuff did not look like road grime. There's about 900km on it so far - should I be worried or just clean it off plug the holes hand see if it comes back? I am pretty sure it was not like that when I picked it up but I guess I could be wrong...