Illegal and unsafe car modifications

25 June, 2024 By Bruce Newton

Modifying your car can sound like a great idea. Maybe you want to carry more gear in your 4x4, make your vehicle handle better or improve your dream machine’s acceleration. Or maybe you just want a cooler look by swapping to bigger wheels.

There are all sorts of modifications that can be made to vehicles from minor, to simple, to complex.

In fact, that’s exactly how Western Australia’s Department of Transport (DoT) classifies them: minor, simple and complex.

Minor is fitting accessories such as roof racks, but we won’t cover minor modifications here. Instead, we’ll focus on simple and complex modifications that require official approval.

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As the names suggest, the more ambitious the changes you envisage, the more complex they will inevitably be. And as Alex Forrest, vehicles and fuels manager at RAC warns, there could well be unintended consequences.

“With most modifications, the vehicle will be better at doing certain tasks, but the costs will mean compromises elsewhere,” he explains.

“A higher vehicle will have better ground clearance but poorer dynamics on sealed roads, while off-road tyres will be better in the mud but likely to lengthen braking distances, especially on wet bitumen. Larger diameter tyres will also affect the accuracy of the speedo, unless it’s been modified accordingly.

“A lower, stiffly sprung sports car will look cool and have sharp handling, but probably a choppy ride and regular contact with speed bumps.”

On top of that, the changes you’ve made may simply not be legal and that means potential fines, defect notices, your vehicle off the road, a failed insurance claim and even costs against you in an accident.

There’s much to consider. So let’s work our way through the process.

Who oversees vehicle modifications in WA?

Each state or territory has control over vehicle registration and therefore modification.

In Western Australia, the Road Traffic (Vehicles) Act 2012 and the associated Road Traffic (Vehicles) Regulations 2014 are the legislative underpinnings that define what you can and can’t do to your vehicle – and here we’re talking ‘light’ vehicles up to 4500kg.

The CEO of the Department of Transport is the Vehicle Regulator for Western Australia. His Delegated Authority is granted to the Vehicle Safety and Standards manager, who approves all vehicle modifications on the CEO’s behalf. Any simple or complex modification made without the approval of the Department of Transport (DoT) is illegal.

The WA Police Force manage the on-road enforcement of defective or illegally modified vehicles and may infringe the owner/driver, impound the vehicle and/or issue a defect notice requiring the vehicle to undertake an inspection at the vehicle owner’s expense.

If all that sounds a bit complex, the DoT stresses that it’s here to help vehicle owners modify and drive vehicles that are legal.

“The Vehicle Safety and Standards (VSS) section of the Department of Transport is staffed by qualified, experienced technical experts who have a range of knowledge and expertise. Many are themselves passionate about vehicles of all makes and models,” was the official DoT response to our questions about vehicle modifications.

Rules and guidelines

Nationally, there are rules and guidelines that also help the DoT develop a cogent modifications policy.

At the top of the pyramid are Australian Design Rules (ADR) that focus on vehicle safety, anti-theft and emissions.

If a vehicle is modified or any equipment added, it must continue to comply with all applicable Australian Design Rules.

For example, an incompatible, incomplete or poorly fitted exhaust system can cause the vehicle to no longer comply with ADR vehicle emission and noise standards.

ADRs have been in existence since 1969 and have evolved in line with technological advancements and increased safety initiatives. Modifications once deemed acceptable on older vehicles are no longer possible on newer vehicles.

Providing further guidance is the National Code of Practice for Light Vehicle Construction and Modification, which is also known as Vehicle Standards Bulletin 14 (or VSB14).

Created in the early 2000s and regularly updated since, VSB14 covers minimum design, construction, installation and performance requirements when modifying a light vehicle.

Perth engineer Jack Packard runs light vehicle modification specialist Packard Automotive. He says there are further complexities.

“VSB14 is nominally accepted by all the states but the way they implement it and interpret it varies. VSB14 isn’t comprehensive so some things sit outside.

“There are things like power to weight restrictions that aren’t in VSB14 that are imposed in WA. It used to be quite a challenging thing to achieve 800 to 900 horsepower on an engine but it’s not anymore. So they [DoT] put power to weight restrictions in there as well.”

Packard agrees it can all be confusing.

“We get a lot of phone calls asking to clarify the process,” he says.

Simple vehicle modifications

The DoT defines simple changes as modifications or device fitment that involves structural changes to the original vehicle, encroachment into occupant protection areas or any reduction in the effectiveness of safety-related areas.

These modifications do not need pre-written approval from the DoT, but usually require a VSB14 checklist completed by a suitably qualified person, such as a mechanic with a Department of Commerce Repairers Certificate.

Examples of simple modifications include seat and seatbelt removal, the fitment of aftermarket fuel tanks, extractors and intercoolers.

The fitment of a manufacturers’ option engine or swapping from a manual to automatic gearbox is also classified as a simple change.

The modification can be assessed by a DoT Authorised Inspection Station (AIS) vehicle examiner at the time of completion, who can issue a modification permit if the vehicle passes the examination.

Complex vehicle modifications

Vehicle modifications classified as complex are individually significant or may involve multiple ‘simple’ modifications being done at one time.

Here we’re talking about major projects like Gross Vehicle Mass and Gross Combined Mass re-rating, engine upgrades that boost power or displacement by more than 20 per cent, engine swaps that aren’t like-for-like (i.e. dropping a Chevy V8 into your diesel Patrol), major suspension modifications that lift the vehicle by more than 50mm and even a change of chassis (i.e. putting an 80-Series Toyota LandCruiser chassis under a 40-Series body).

A report by a DoT-recognised automotive consultant needs to be provided to VSS as part of the certification process, to show compliance with VSB14.

Automotive consultants are individuals or businesses that have been recognised by DoT as being able to produce engineering evidence, and reports are published on the DoT website. Packard Automotive is on the list.

They must personally inspect each modified vehicle and ensure that any construction or modification of a vehicle complies with the requirements before issuing a comprehensive engineering report.

Upon completion, the automotive consultant’s report is submitted to VSS for assessment and if approved a DoT written approval is issued.

The vehicle is then inspected at an AIS and a Modification Permit issued upon payment of a prescribed fee, to demonstrate that the modifications have been approved by the DoT.

“If you know the rules well enough you can do quite a lot,” says Packard. “There are restrictions … but most people are relatively happy with what they can achieve.

“The biggest bugbears are tyre size and exhaust volume. The noise limit is 90 decibels for vehicles built after 1986 and 96 decibels before then.

“Tyre size on 4x4s is the big issue here. The limit is a 50mm increase in the rolling diameter of the tyre. It’s a hard rule and the only way around it is to change the axles out of the vehicle, because the axle is what the rating is applied to.”

The consequences of getting it wrong

RAC’s Alex Forrest says the ramifications of vehicle modification can be multiple and need to be thought through.

“The more changes that are made to a vehicle to suit your preferences, the narrower the appeal becomes to potential buyers when it comes time to sell the vehicle,” he explains.

“Sure, the changes you made will probably appeal to others with similar tastes, but more buyers will be interested in a largely unmodified vehicle, and resale values typically reflect that.

“Reliability and wear items may be affected, such as universal joints and wheel bearings on vehicles with raised ride heights, wheel spacers and bigger wheels and tyres.

“If the engine has been modified, it may use more fuel and if the exhaust has been changed, owners will need to ensure the vehicle still complies with the noise and emissions regulations it was originally sold under. Otherwise, it’ll risk the dreaded yellow (defect) sticker.

“Voiding the vehicle’s warranty – if it’s still covered – is another consideration. If a failure can be traced back to an aftermarket modification, there’s a good chance any related warranty claim will be knocked back.

“And you may need to update your insurance coverage if the vehicle has been changed significantly, and if its value has changed.”

Further to that, illegal modifications made to a vehicle exposes the owner and any driver to the risk of not being covered for injuries caused to others if the vehicle is involved in a crash.

“The vehicle owner or other driver of an illegally modified vehicle that is found to be at fault for a crash may be requested to repay all monies paid by the Insurance Commission of Western Australia for the treatment, care and compensation of an injured party’s claim,” the DoT explains.

Get the right information before you start

Alex Forrest says there are plenty of ways to make changes to your vehicle that better suit your tastes and needs while also keeping it safe, legal and retaining its resale value.

“Drastically modifying your vehicle may make it look or sound cool, but if it’s also going to be driven daily, it’ll pay to consider what it’s going to be like to live with.

“Speak to owners of similar vehicles and ask them about the real pros and cons, and how they affect the vehicle over the longer term.”

It also helps to check in with the experts like Jack Pollard who can navigate you through the legalities.

“Consider the sources of your information too – YouTubers can be helpful, but often put forward a certain lifestyle for the cameras without adequately addressing the pitfalls. And remember they often have something to sell and click numbers to achieve.”

Ensuring the changes are legal is very important, as is checking to see how the warranty is affected. If all that checks out, you could be a step closer to making your vehicle more ‘you’ than it’s ever been.