Help centre

The short answers to the most common questions

Do I need an account?

Not to build a plan. The full plan is free with no account, no email and nothing held back - every phase, every part, every price and every warning. You need an account only to save a build, and the Free tier saves two of them. An in-progress build is kept in your browser's local storage, so a reload will not lose it.

Why are the prices ranges?

Because we have no affiliate product feed and no live pricing API, so a range with the date it was checked is more honest than a precise number we would have to invent. The date is shown on every part. Retailer links say "check price at X" and take you to the retailer for the real figure.

What do the confidence badges mean?

How much we actually know. Verified means we or a cited source confirmed it on that specific chassis, and the source is on the page. Community-reported means owners-group or forum consensus, linked but not independently confirmed. General principle means it is true in general and you should measure your own car. We never claim a fitment guarantee.

What happens if I cancel?

You keep Pro until the end of the period you have paid for, then the account drops to Free. Nothing is deleted - anything over the two-build Free limit becomes read-only, and we will export your data on request whatever plan you are on.

Something is wrong in the catalogue. What do I do?

Tell us, and a wrong fitment claim is the most useful report we can get. Say which chassis, which part and what actually happened, and we will either correct it or downgrade its confidence level - and we will tell you which. For a price, a link to a current listing is the most useful thing to send.

Is any of this safety advice?

No. It is build planning. Safety equipment requirements vary by organiser and by region, certifications expire on paper, and your series' rulebook is the authority. Where we mention a safety item we tell you to check the rulebook, and we mean it.