I'm just taking a stab in the dark but maybe the other 3 wheels have been repainted and that one still has the original coat which has been corroded by brake dust. That would explain the lack of rock chips on the other 3 wheels.
I didn't take enough care of my OEM wheels and they looked horrible with all this baked on brake dust. No matter how hard I tried I could not remove it. Someone crashed into me and I had one wheel repainted and I found that the repainted wheel was much easier to clean because the paint on it was fresh.
I've now since painted them all flat black and last weekend I took them off and nano sealed them with Gtechniq C5 Wheel Armor. Hopefully that'll keep them nice and shiny and stop that pesky brake dust from eating into the coat.
Procede Rev 3 | PWM Meth | Mr5 Intake | AFE Scoops | ER FMIC | ER CP | TiAl BOV | AR Catless DPs | CP-E Exhaust | Forgestar F14s | M3 Strut Tower Brace | M3 Front Arms | M3 F + R Sway Bars | M3 Rear End Conversion | Moton Clubsports with Swift Springs | Vorshlag Camber Plates | ECS 2-Piece Rotors | SS Lines | Cool Carbons | BR Half Cage | BMWP SSK | BMWP Interior/Exterior Goodies | Blacklines | P3 Gauge | 1M Interior |