I noticed this the last time I rotated my tires (8000kms). today I rotated again and they don't seem to be any worse, however the only ones affected are the front ones the rear are perfect. my question is, is this normal? I ask cuz I don't want to ask the dealership so they push me to get new ones. that being said I cleaned them up and applied clear finger nail polish to them. this is what they look like now and I will see what they look like when I rotate again.