James, the car CAN be removed from the premises between test and retest. Sounds like your garage is trying it on.
Directly from the back of the failure certificate:
"Retest Charges
The maximum fees charged for retests are:
a. If the behicle is left at the test station that undertakes repairs, for repair and retest, then onlt a partial retest is required. - NO FEE
b. If the vehicle is brought back to the test station and retested before the end of the next working day on one or more of the following items only: ABS warning, Bootlid, Brake pedal antislip, Direction Indicators/hazard warning, Doors, Dropsides, Exhaust emissions, Fuel filler cap, Headlamp aim, Hoen, LAMPS, Loading door, Mirrors, Rear reflectors, Registration plates, Seat belts (but not anchorages), Seats, sharp edges, projections, Steering wheel, Tailboard, Tailgate, VIN No, Wheels* and Tyres* and Winscreen wipers and washers; only a partial retest is required. - NO FEE
* does not apply to Classes i or ii
c. If the vehicle leaves the test station premises and returns for a retest on item(s) other than those listed at b above the behicle must be fully inspected on all tstable items before a test certificate may be issued. A full test must be carried out even if a "free retest" is offered for marketing purposes. - FULL FEE"
Note, at the beginning - "The MAXIMUM fees charged...
Go get 'em!
Ken
Edit: D'oh! Took so long typing that, you worked it out yourself.