I kept repainting my with spray paint, and it always rechipped. Even after I sandblasted right down to metal, repainted and did a clearcoat layer, still chipped all over the place. So I had them powdercoated back in '08....not a single chip since:
Who needs windshield wipers anyways, rainx FTW. But if you must have them, then regular spray paint has always held up fine for me, never had an issue with flaking/chipping paint either
I painted mine over the fall with semi gloss black spray paint and they've been good so far. Both my fronts were bare metal, you'd get a nasty sun glare off of one of them.
Take a grinder wire wheel to them and get it down to bare metal. Then put several good coats of primer followed by several good coats of semi flat back paint. You should be good to go. Take your time and do it right and you won't have flaking and chipping.