"7.2 Surface Films (Window Tinting)
These requirements apply to all vehicles irrespective of their date of manufacture and are
controlled by the Australian Vehicle Standards Rules (AVSR).
Surface films reduce light transmission through windscreens and windows. This can significantly
reduce a driver’s vision, particularly at night and during periods of low visibility.
If windows, other than the windscreen, of a motor vehicle are coated to reduce light
transmittance, the following requirements apply:
For the windows forward of the rear of the driver’s seat luminous transmittance must not
be less than 70% when measured through glass and film together unless the laws of a
State or Territory allow a lesser luminous transmittance. The lesser transmittance must
be above 35%. (Figure LZ-G2 illustrates the window tinting requirements in terms of
luminous transmittance for passenger vehicles.
It also specifies the different
requirements currently in force in the Northern Territory);
For windows behind the rear of the driver’s seat the luminous transmittance must not be
less than 35%;
Reflectance in the visible light range must not exceed 10%; and
The coating must not be wrinkled, blistered, bubbled or discoloured such that visibility
through the glass and film is impaired.
The prohibition for coating the windscreen does not apply to the greater of the following areas of
the area above the highest point of the windscreen that is swept by the windscreen
the upper 10% of the windscreen.
Vehicles fitted with surface film must be equipped with an external rear vision mirror on both
sides of the vehicle."
They also mention "Note: Since the AVSR allows jurisdictions to set alternative limits for window tinting, it is
important that the jurisdiction in which the vehicle is to be either registered or
used, be contacted for that jurisdiction’s specific requirements"
So, a minimum standard would be that blue tint 10% area on top of the windscreen. Any more than that would probably raise an eyebrow with someone that has nothing better to do than nitpick..