You have tweaked a mystery for me. Last spring, I bought a 2006 BMW in Nevada. The car had spent all of its one-owner life in Los Angeles and appears to have been wholesaled to a dealer in Las Vegas, where I found it.
I'd previously bought a used car in Monterey CA and was pleased that its paint had no rock chips and the original windshield was like new. Not so my latest purchase. The glass and paint are as pitted as if the car had spent its first six years here in Edmonton, where the City dumps sand and gravel on icy roads all winter long. The hood badge has hardly any paint left on it.
I've driven in LA and I know the roads are clean and pothole-free - well, relative to the frost-crated cart tracks around here. What would cause this pitting on car surfaces in southern California? Excessive sun? Dust storms? Nasty kids with pellet guns?