The single stage actually provides better UV protection over bc/cc. Clearcoat has hardly any pigmentation in it provide good UV protection.
To get maximum depth in your finish wetsand with no courser than 1000 after you paint and let cure overnight. Then reshoot the car again, then cut and buff. Youíll be amazed at the depth and gloss youíll achieve. Itíll be a mirror finish when done. Pretty much like milo,s photo in his post.