Avoid getting pulled over by the police because you were not able to comply with the car window tinting laws as you will also have to remove them after. So if you get pulled over, that does mean that it is illegal to tint your car windows?
Window tinting is definitely legal in Australia. You just have to follow the law in your state or territory and you are all safe. There are also different legal things for private and commercial vehicles, which means the darkest legal tint meant for commercial vehicles is illegal for private cars. But there are also exceptions to that too and that is if you obtain a written permission from your doctor explaining why you can have a darker tint.
For commercial vehicles
If you drive a commercial vehicle the amount of visible light transmitted (VLT) that is allowed are 20%, 15% and 5%. The darkest is 5% which is good if you want to protect your privacy and intellectual property.
For private vehicles
The allowed VLT for private vehicles is 35% and 10% on the uppermost part of the windshield. You are not allowed to use commercial-grade tints for your vehicle except only if you have a special permission given by your physician or skin specialist outlining why you need to have a dark window tint on your vehicle.
If you still want commercial grade tints even if you own a private vehicle make sure to get the proper documentation first since the pros will not put your chosen tint if you do not have the right papers from your doctor, or you could just follow the law and use the right tint meant for your vehicle.