How this site works

Methodology and corrections

Carmodfinder publishes road-legality verdicts for vehicle modifications. This page explains how those verdicts are reached, what they do not cover, and how to get one changed if it is wrong.

How a verdict is reached

Start from the law, not from opinion. Every verdict traces back to a primary source: the statutory instrument, the government inspection manual, the regulator's own guidance, or the state vehicle code. Forum consensus and retailer marketing are not sources.
Read the actual text. The cited provision is read in full rather than quoted second-hand from another article. Where a rule has been amended or repealed, the current version governs.
Separate the equipment from the use. Many rules restrict how a part is used on a road rather than whether it may be fitted at all. Those are different questions and the verdict says which one applies.
State the conditions. Most modifications are not simply legal or illegal. The conditions that decide it are listed on the page, so a reader can check their own case.
Link the source. Every legal claim carries a link to the provision it rests on, so the reasoning can be checked rather than trusted.

What the verdicts mean

Legal. Permitted on a public road in that country, assuming the part is fitted correctly and meets any general requirements that apply to all vehicles.
Conditional. Legal only within stated limits, or legal to fit but restricted in use. The conditions on the page are the point, not the badge.
Not legal. Not permitted for road use in that country. Where a compliant alternative exists, the page says what it is.

Jurisdiction

Road-legality is national, and in the United States frequently state level. A verdict applies to the country named on the page and nowhere else. Where a rule varies by state or region, the page explains the framework and points to the authority that sets the limit, rather than reproducing a table of numbers that would silently go stale.

What this site is not

It is not legal advice, and it is not a substitute for an inspection, your insurer, or the vehicle manufacturer. Rules change, vehicles differ, and enforcement varies. Anything expensive or irreversible deserves confirmation from the relevant authority before you commit to it.

Keeping pages current

Legal claims are reviewed against their sources periodically, and the review date is shown at the bottom of each legality page. Sources were last reviewed in July 2026. When a rule changes, the page is updated and the verdict changes with it.

Who writes here

Articles and guides carry a byline. Each writer covers the areas below.

Martin

Editor

Runs Carmodfinder. Spends more time under cars than in them, and has read more of the Construction and Use Regulations than is strictly healthy.

Alex

Suspension and chassis

Covers suspension, brakes and everything that changes how a car turns. Convinced most handling complaints are really tyre complaints.

Brandon

Engine and forced induction

Writes about boost, engine builds and supporting mods. Has fitted turbos to several things that arguably did not need one.

Thomas

Exhaust and emissions

Follows exhaust rules, emissions equipment and what actually passes an inspection. Keeps the receipts for every part he fits.

Louis

Wheels and styling

Covers wheels, fitment and the cosmetic mods most likely to get a car pulled over. Daily drives something lower than he admits.

Affiliate links

Some pages carry a clearly labelled sponsored link to a retailer, marked Ad, and Carmodfinder may earn a commission if you buy through it. That arrangement never decides a verdict. A modification that is not road legal does not become legal because somebody sells the part, and no retailer sees a verdict before it is published.

Corrections

If a verdict or a cited provision is wrong, tell us and it gets fixed. Email support@carmodfinder.com with the page URL and, if you have it, the provision you believe applies. Corrections to a legal claim are made on the page itself rather than quietly, and the review date is updated when the change lands.

We would rather be corrected than be confidently wrong. A page that cites its sources is one you can argue with, which is the whole point of citing them.

Sources last reviewed July 2026.