Seems like things have changed slightly.
Phil is right if the car is bought unfit, however most aren't unless you are buying a salvage or crashed vehicle.
The whole point of a temp permit was so that you can get a safety n etest.
Temporary vehicle permits
A temporary vehicle permit allows you to drive for short-term purposes only. For example, you can use this permit to drive a vehicle to a:
garage (e.g., to satisfy Safety Standards Certificate or Drive Clean requirements)
Get a temporary vehicle permit
According to this:
You can get it as long as when the seller gives you and signs the ownership it is in a 'fit' state.
Before they allowed you to do the transfer making it unfit until you complete the process.