If you buff it out, don`t apply any wax that seals the paint. Spray paint needs 3 to 4 weeks to completely dry, as it depends on evaporation to cure . If you seal the finish before it fully cures, it will turn dull and chalky in a short time.
You can still buff it after a couple of days of drying, just don`t use a wax or sealant on it for a few weeks.
Meguiors #7 is a great polish for new and old paint, and can be machine or hand applied.