I would guess you are going to need a repaint/ the body shop is going to need to respray the area.

Now I'm only guessing (and I hope I'm wrong) but the fact that they buffed it, it disappeared, but then reappeared means that it is some type of reaction occurring as the fresh paint outgases (the solvents are still evaporating.) Does your car still smell like fresh paint?

I would let it sit (maybe in the sun) for a couple of days, then try polishing it. See if it comes back. I would imagine it will come back, but it may take longer to do so.

I would also stress your concerns to the bodyshop. If the paint is doing this something is wrong (not sure what) but it would stink to have the paint fail in that area a couple years down the road and have them stiff you because its out of warrenty or whatever.

If it was my car I would want the paint taken off those areas (back down to metal) and I would want them resprayed from the ground up.

 

Yea it sucks but I think I might have to get it repainted. I went and got a clay bar and it took some of it off but I have to really clay it hard for it all to come out and Im scared that it'll come back like when it was buffed.

 

id just have them repaint it. if that fender is fresh then u really shouldnt be buffing it at all.