Says on the RMA website:
An exemption from the prohibited vehicle condition may be granted if:

*A prohibited vehicle needs to be driven for genuine employment purposes.
*Eight or more cylinder 4WD vehicles are required by country drivers who have no practical alternative.
*You can prove direct ownership of a prohibited vehicle prior to the start of the scheme or before an overseas/interstate licence transfer.
*The vehicle is a moderate-performance turbo/supercharged engine vehicle.

Volkswagen 1984cc Tiguan 125TSI, 132TSI, 155TSI and Passat 147TSI
There was also exemption available if you could prove it was the only vehicle available in the household.

I don't think age comes into it - that is for carrying passengers.

What a mish-mash of a web page.