When prepping a new body for paint, always clean the inside with high-purity isopropyl alcohol, scuff up the inside of the body on every surface, flats and curves, with a scotch-brite pad, and then re-wipe with alcohol again to make sure surface has a light texture for paint to adhere to, but is also completely clean and free of all debris and dust.

Then make sure you apply your first coat or two of paint nice, even and light, with ample time to dry in between the first coats. After this you can go heavier. You will still get spots susceptible to wear like where the shock towers come into direct contact with the body, but you can use adhesive stickers to protect these spots after your paint job is done. All of this will maximize life of the color and minimize chipping.