What Counts as a Modification?

In insurance terms, a modification is any change made to a car that differs from the original factory specifications, regardless of whether it’s functional, cosmetic, or performance-related.

Common examples include:

Alloy wheels or aftermarket rims
Engine tuning or turbocharging
Suspension lowering/lifting
Body kits or spoilers
Custom paint, decals, or wraps
Upgraded sound systems, lights, or exhausts
Even small changes like adding a dashcam or window tints may need to be declared.

How Do Modifications Affect Your Insurance?

Insurance providers treat modified cars differently because of increased risk and repair costs:

Higher Theft Risk: Modified cars are often more attractive to thieves.
Increased Crash Risk: Performance upgrades may raise accident likelihood.
Costlier Repairs: Custom parts and labour are more expensive to replace.

As a result, you may see higher premiums, reduced cover, or additional policy conditions.

Do You Have to Tell Your Insurer?

Yes—absolutely.

If you don’t disclose a modification, your insurer might:

Refuse to pay your claim
Cancel your policy
Offer only partial reimbursement

Whether it’s a stereo upgrade or a performance tune, always declare changes to avoid issues later.

Will the Modifications Be Covered?

This depends on your policy and insurer. Some will:

Accept the mods with no premium change
Charge extra or increase your excess
Require specialist or performance insurance
Exclude coverage altogether

Luxury upgrades or performance changes (e.g. turbos) usually need agreed value cover or specialist policies.

Tips to Stay Protected

Check before you mod: Ask your insurer if your planned change is covered
Keep receipts: Document every upgrade
Get agreed value: This can better reflect your car’s modified worth
Review cover regularly: Update your policy as you continue to modify your car

Final Thoughts

Modifying your car is a personal choice—but it’s also a financial risk if not managed correctly. In New Zealand, insurers expect full transparency. By understanding what’s covered, declaring all changes, and comparing the right policies, you can enjoy your modified car—without compromising your protection.