If driving connects to your movement through your life and a destination is the consciousness of something to be expressed, then the valet is the representation of the part of you that makes sure your access to your movement through life (your car) is well cared for when you are having an experience. Your relationship and sensation around what happens with the valet in your dream will inform your interpretation. [1]
If you dream of being the valet for someone else, then you may be venting out feelings of victimhood and of taking better care of others than you do of yourself.
See also: Parking Attendant. [2]