How to Declare Car Modifications to South African Insurers

17 August 2026

A modified car is not automatically uninsurable. The problem starts when the owner treats the insurer like a spectator instead of a counterparty. If the car no longer matches factory spec, the policy has to match the car, not the brochure.

People often try to skip this part. Remaps, exhausts, suspension changes, rims, sound gear, turbo upgrades, brake swaps, even a lift kit on a bakkie all change the risk the insurer priced. Leaving them out is not clever. You are building a claim dispute and hoping nobody notices.

The rule is simple

Declare anything that changes the car’s value, performance, safety, theft appeal, or use from factory spec. This is the practical line insurers use, and it covers far more than the loud bits.

A remap is obvious. If ECU software changes power, torque, throttle response, fuel use, or deletes emissions equipment, it must be disclosed. A performance exhaust is the same story. So is a lowered suspension setup, coilovers, air suspension, lift kits, aftermarket alloys, wider wheels, uprated brakes, a turbo or supercharger swap, and a body kit.

OUTsurance is blunt about accessories. It says that if you have not specified non-standard vehicle accessories, cover for those items is not there, and any extra items you add need to be listed individually. Its examples include mags, boot spoilers, leather seats, tow bars, bull bars, and extra dials, and it says specified items carry an additional premium. King Price is equally direct on performance. Its FAQ says you must tell them about modifications, alterations, or performance enhancements, and it adds that damage caused directly or indirectly by a car modified to alter its performance is not covered under that wording. [OUTsurance non-standard accessories, accessed August 2026; King Price FAQ, accessed August 2026]

Many owners miss this. Insurers care about more than just flashy parts. A set of rims, for example, is not just cosmetic if it pushes the car into a different theft bracket or increases the replacement value by tens of thousands of rand. A suspension change is not just about stance. It changes handling, ride height, and sometimes the shape of the claim if the car ends up bent or rubbing through tyres after a pothole run.

What must be declared

Here is the short version for the usual suspects.

Remaps and ECU tunes must be declared. A tune that raises power or torque, or changes fuel mapping, changes the risk profile of the car. This includes performance tunes and economy tunes. It also includes software changes done to support hardware or delete equipment.

Exhausts. Declare aftermarket systems, especially cat-back systems, full systems, downpipes, and anything fitted to chase power or noise. Even when the exhaust does not add huge power, it still marks the car as altered and can affect how an insurer views the vehicle.

Suspension. Declare springs, shocks, coilovers, air suspension, lowering kits, and lift kits. These change ground clearance, body control, and the likelihood of secondary damage. If the car sits differently from factory, the insurer should know.

Rims and tyres. Declare aftermarket wheels, especially if the size, offset, width, or value differs from standard fitment. Tiger Wheel & Tyre’s public pricing shows how quickly wheel and tyre costs climb. Its wheel listings run from about R1,342 to R6,067 per wheel, while tyre listings go far higher, with many passenger tyres in the low thousands and some premium SUV sizes above R6,000 each. [Tiger Wheel & Tyre wheels and tyres, accessed August 2026] A full set of decent alloys is not pocket change, and insurers know it.

Brakes. Declare bigger calipers, performance pads, drilled or slotted discs, and other brake upgrades. These are safety-minded changes, but they are still non-standard and can raise the car’s repair value.

Forced induction. Declare a turbo or supercharger if the car did not leave the factory with one, and declare major upgrades to the existing unit. This modification changes the whole underwriting conversation.

Sound gear and other accessories. Declare permanent aftermarket audio, subwoofers, amplifiers, spoilers, tow bars, leather trim, seat conversions, and similar fitments. OUTsurance says factory-fitted sound gear is automatically covered as part of the vehicle value, but anything added later has to be specified. [OUTsurance sound equipment cover, accessed August 2026]

If you are unsure whether something counts, declare it. The safe answer is almost always cheaper than the argument after a theft or smash.

How premiums move

Most declared modifications push the premium up. Not every change does, but the average direction is upward because the insurer is taking on more value, more variation, or more risk.

The most straightforward reason is replacement cost. A stock Polo Vivo and a Polo Vivo with imported wheels, a quality exhaust, a suspension kit, and audio gear are not the same financial object. If the modified car is stolen or written off, the insurer has to deal with the added hardware, not just the base car.

The second reason is theft appeal. Desirable parts go missing. Wheels disappear at fitment centre speed. Tailor-made audio and performance parts can be sold separately. A modified car can therefore become a more attractive target than a standard one sitting next to it at the robots.

The third reason is underwriting comfort. A modification done properly by a reputable shop is easier to price than a garage-job special with missing invoices and no paper trail. Insurers are not sentimental. They price what they can verify.

King Price’s own writing makes the same point in plain terms. It says changes to the car can affect the premium, while also noting that not every modification increases the premium. Security upgrades like an immobiliser, tracker, or rear sensors can improve the risk picture instead of harming it. [King Price cost article, accessed August 2026]

This is the useful distinction. Performance changes usually cost money in premium. Security changes can reduce risk and sometimes help the price. A remap and a tracker are not the same thing, even if both were fitted in the same week.

What happens if you leave it out

Non-disclosure is where people get hurt.

King Price says a material omission can lead to a rejected claim or cancellation of the policy. Its claims article specifically names vehicle modifications as a common reason claims get turned down, and says failure to disclose them can invalidate the claim. [King Price claim rejection article, accessed August 2026]

The South African government’s 2013 statement on insurance disclosures says the industry would not reject claims for minor incidents that are not material to the risk, but it also says consumers should report material information in line with policy conditions. This is the line that matters here. A modified exhaust or turbo conversion is not a scratched bumper. It is material. [South African Government media statement, 11 April 2013]

The consequences are ugly and practical, not dramatic.

The claim can be repudiated. The insurer can cancel the policy. You can be left covering the full repair or replacement cost yourself. If the car is financed and written off, the problem can grow fast because the payout follows the insured value, not your debt balance. If you have a modified car worth R300,000 and it disappears in a theft claim that gets rejected, that loss lands on you, not the insurer.

A claim rejected for non-disclosure can make the next insurer look at you sideways, which usually means more questions, higher premiums, or a harder underwriting process. This is before you get to any fraud allegation if the omission was deliberate.

The clean reading is this: if the mod matters enough to improve the car, it matters enough to tell the insurer.

What proof you should keep

If you declare it properly, back it up properly.

Keep invoices for parts and fitment. Keep the fitment shop’s details. Keep photos before and after the work. Keep a dyno sheet if the car was tuned. Keep a valuation if the build is more bespoke than the normal insurer spreadsheet can handle.

That paperwork is not decoration. It is how you prove what was fitted, what it cost, and what should be included in the sum insured. King Price says a valuation certificate is needed for collectable cars where there is no standard industry value, and that the agreed value must include non-standard fitted extras and accessories. [King Price collectable car cover, accessed August 2026]

For performance work, a dyno sheet is the closest thing to honest language. It shows what changed, and by how much. Without it, you are asking the underwriter to price your pride and optimism. That usually ends badly.

Insurers that openly deal with modified cars

A few mainstream names are willing to engage, provided you are honest and specific.

King Price is the most openly modification-friendly on its public wording. It says modified vehicles can be handled through agreed value cover, and that agreed value is especially suitable for modified cars because aftermarket upgrades are included in the agreed amount. It also says the agreed value must include non-standard fitted extras and accessories. [King Price collectable car cover, accessed August 2026; King Price theft or write-off article, accessed August 2026]

OUTsurance is clear on specified accessories. If you add items beyond factory spec, they need to be declared and separately covered. It also says specified accessories attract an additional premium. This makes it a practical option for owners with wheels, audio, spoilers, or other fitments they want protected. [OUTsurance non-standard accessories, accessed August 2026]

Santam’s public vehicle cover page lists optional specified accessories, tools, spare parts, travel accessories, and accidental damage to tyres and rims. This is not the same as a dedicated modified-car policy, but it does show a willingness to insure non-standard items when they are declared and properly priced. [Santam vehicle cover, accessed August 2026]

Momentum Insure’s public pages describe flexible cover and optional extras, and its wording makes clear that you can customise the policy to suit the vehicle. The public pages do not market themselves as a hardcore modified-car specialist, but they do show a willingness to add and price extra cover when the risk is explained cleanly. [Momentum Select, accessed August 2026]

For heavily modified cars, specialist brokers still matter. Once the build moves beyond bolt-ons into engine swaps, custom fabrication, or agreed-value territory, a broker who understands the car is usually the least painful route.

The practical way to do it

Tell the insurer before or as soon as the mod is fitted. Do not wait for renewal. Do not assume a small change is beneath notice. Give them the part names, the fitment date, the cost, the shop, and the invoice.

If the car is already modified and the policy is silent, fix that before you drive another kilometre. The premium may move a little. The quote may change more than you hoped. That is still cheaper than losing a claim over a set of rims or a tune you thought was too minor to mention.

The right test is simple. If the modification changes what the car is, declare it. If it changes what the car is worth, declare it. If it changes what can go wrong, declare it.