nah, he doesnt have to deal with the cops first. a permit to drive from the cops would be useless if its not rego'd as even with the back of the defect paperwork is filled out your not legally allowed to drive a unrego'd car (stating the obvious, i know)
all he needs in a regency date before he goes into rego a defected car. the car does not have to be with you just your rego and defect forms.
they will check your regency date, or at least wait on hold for as long as they can stand and have to take your word for it.
once it has the manual rego filled out, he can get a permit from the cops (the back of the defect paper work filled out) to drive the car around while defected.
you are allowed to drive a defect car without a permit if you are going to the cop station to get a clearence to drive.
BE WARNED, if a cop pulls you over and the mods listed on defected paper work are not actually cleared, he holds all right to pull your permit to drive till your regency date an youll be up shit creek as your car will need to be towed.
i have done this more then my fair share. i used to always for some reason get defected just before my rego ran out
EDIT: i just re-read what you wrote chad. the rego office doesnt have to have a clearence on the back of the defect notice before giving temp rego. if thats what you meant?