Defective Cars

By Angela Monroe - May 11, 2021

Australia has some tough regulations on defective cars. Meeting roadworthiness requirements is often something most motorists aren’t aware of – until it’s too late.

We take a look at some of these requirements in Australia’s states and territories.

What’s the deal with defective cars?


It means a vehicle has been found not meeting safety or drivability standards. Commonly, it happens when a police officer comes across a vehicle that doesn’t comply with regulations and upon inspection, issues a ‘defective vehicle notice’, also known as a ‘getting defected’.

A defective vehicle sticker (often bright yellow) is displayed on the windscreen of the vehicle. In more serious cases, a car may need to be towed or transported away from where it has defected.

It can be frustrating and expensive for motorists found to be driving defective cars, but keeping cars roadworthy helps keep all people on the road safe.

Defective car process

In most states, after getting defected, a car will only have 24 – 48 hours to remain on the road. This is to allow the driver to get home and/or get the vehicle to a mechanic.

The notice will list some of the defects found and often require the vehicle to pass a state government inspection.

In some states, if only a minor defect is found, a car might require a repair by a qualified mechanic to have the defect notice removed by local police. If multiple defects are found, the car will likely need a full inspection and pass a roadworthy test.

Typically, a car must be repaired with a certain timeframe or risk having the registration suspended. This means the driver will need to tow or transport the car on a truck.

Different states and territories have different requirements, so check with your state’s laws on defective cars.

What can you get defected for?


There are a huge number of issues that can deem a car unroadworthy. Other than the big one; safety, things like noise pollution, emissions and modifications also get looked at.

Here are a few of the common things that vehicles get defected for

Too low 

This defect is often caused by modifying a car’s suspension. When a vehicle’s ride height is considerably lower than the factory configuration, some of the handling characteristics are unsafe for public roads. This is common with performance vehicles.

The same can be said for raised suspension. Sometimes a vehicle may be found defective if sitting too high. Some 4×4 vehicles use lift kits to increase ground clearance.

Too loud


Again, this issue is common for modified cars. In most Australian states, the exhaust volume limit is 90 decibels. Cars that are extra loud can attract defects. Some older vehicles may have a limit of 96 dB.

To find the volume of exhaust, police or vehicle inspectors will place a dB meter around 1 metre away from the exhaust (at the rear of the vehicle) while revving the engine.

  • Is 90 dB loud?

Decibels aren’t measured on a linear scale. Silence is 0 dB. A sound 10 times louder is 10 dB. Noise 100 times louder than silence is 20 dB. 1,000 times louder than silence is 30 dB.

  • A whisper – 15 dB
  • A normal conversation – 60 dB
  • Vacuum cleaner – 75 dB
  • Shouted conversation – 90–95 dB
  • Jet engine from 100m away – 135 dB
  • Shotgun blast – 160 dB
  • Rocket launch – 180 dB



Headlights, taillight or turn signals that don’t work are a common issue on defective cars. Fortunately, these are easy to fix. Most mechanics will check a car’s lights when they service the vehicle and replace any LEDs or lights that aren’t working.

Sun faded headlights can also be defective if really bad. This is a yellowish discolouration on the surface of headlights and is caused by UV light exposure. It can significantly reduce visibility at night.

Fortunately, it’s a quick fix. If your headlights are faded, use a headlight restoration kit to bring them back to life.

Window tint

Tinted windows really help in Aussie summers but too dark and mean a defective vehicle. This is due to visibility, especially at night but also for people (law enforcement) looking into a vehicle too.

Different states have different regulations on tint level. Window tint is measured in VLT (Visible Light Transmission) which is usually a percentage, the higher the VLT, the more light passes through. A clear window is around 95% VLT. The dark tint might be 15 – 12% VLT. No state in Australia allows windshield tint.



Another ‘old classic’ defect. Bald, heavily worn or damaged tyres can often result in a defect. If this is the only issue found with a vehicle, it might simply require new tyres to get the defect notice removed.

Tyres have wear indicators in the tread patterns which indicate when they need replacing. These are raised ridges within the tread. Next time you go in for a wheel rotation or alignment, ask a professional when your tyres might need replacing.


car smoke

If vehicles are blowing smoke, they’ll likely be deemed defective cars. Not only are cars with excessive smoke defective, but they also likely trigger a ‘check engine’ light and might be in desperate need of repair.

  • Black smoke usually means your car is burning too much fuel compared to the oxygen level.
  • Blueish smoke typically means oil is being burned. This happens when oil leaks into the engine combustion chamber.
  • White smoke hopefully isn’t smoke at all – it might be condensation from a worn exhaust on a cold morning. However, it could also be something serious like a coolant leak if the white smoke doesn’t stop.

The down-low on defective cars

new car

Driving a defective car can be a common driving mistake that many people make. Generally, new cars in good working order are safer and much less defective than older or modified cars. 

If your car is feeling a little old or defective, it might be worth upgrading to a new vehicle in better condition. Although easy said than done, it’s still much easier than it used to be with a car loan at a competitive rate.

Angela Monroe
Angela Monroe is the Community Manager at The Positive Group, specialising in giving people the information that they need when they need it, and putting you on the path to a fair financial future. She has 8 years of experience in helping Australians find the right finance solutions, and regularly contributes articles to empower Australians with the knowledge they need to become financially healthy.


No comments yet.

Sorry, the comment form is closed at this time.

  • Quick Quote

  • Related Posts