You are going to get chips with these cars; it's part of the deal. Even with a super hard commercial urethane finish, the cars just sit too low and they attract everything. I got upset with the first one or two, now I just get out the touch-up bottle and dab some color on them. Look at my gallery...car looks stellar. If people point out the chips, I just tell them, "Yup, I drive it like Steve McQueen."
Single stage industrial solids are probably the most chip resistance for street driving (I have this on my Z06, and it's still bad). All two stage color/clear finishes were designed to look pretty and not be as durable. Mercedes paint is incredibly hard and durable (has ceramic in it), but for some reason it also scratches easy and is a b**** to buff out.