The answer to this depends on the condition of the paint finish. Basically, there are three types of paint finish conditions: Bad, moderate or good.
A bad finish could require a heavy or medium compound for correction, then a polish, wax or sealant.
A moderate finish might require a light compound, polish, wax or sealant.
And, finally, a good finish would require polish and wax or sealant.
With an auto dealer or wholesaler whose vehicles might have a moderate or good finish, you can use a one-step cleaner glaze with a high-speed buffer or orbital waxer.