Guide
How to document your car build and keep a mod list that holds up
Most modified cars have a mod list that lives in the owner's head. Then someone asks what turbo it is, or a buyer asks who did the work, or an insurer asks what was fitted, and the answer is a shrug and a search through old messages.
Keeping a proper list is not hard. It is a few fields per part, a handful of photos and a habit of updating it. This guide shows what to record, with a template you can copy into a spreadsheet or a notes app.
Updated October 9, 2026
Why bother
- Selling. Buyers want to know what was fitted, who installed it and when. A clear list answers that before they ask.
- Insurance and claims. A dated list with receipts is much easier to work from than memory. Ask your insurer what they need for modified vehicles.
- Your own sanity. You will forget a part number the day you need to reorder it.
- Showing it off. A clean list is also what you put on a display card or behind a QR code.
A mod list template you can copy
Make one row per modification and fill in as much as you know. Missing fields are fine. A half-filled row beats no row.
| Field | What to put |
|---|---|
| Part | What it is, in plain words. For example: intake, coilovers, wheels. |
| Brand and model | The maker and the exact product name. |
| Part number | The number on the box or the invoice. It settles every argument later. |
| Date installed | Even an approximate month. Dates let you match parts to photos. |
| Installed by | You, or the shop that did the work. Buyers and insurers tend to ask. |
| Cost | Parts and labor, if you want a running total. Optional. |
| What it changed | One line. A number if you measured one. |
| Where you bought it | A link, so you can reorder and others can find it. |
| Receipt | A photo or a file name for the invoice. |
Group the rows by type so the list reads well later: engine, drivetrain, suspension and brakes, wheels and tires, exterior, interior, electronics. That is also how people expect to read a build sheet.
Take photos before you start
Photograph the car from every angle before anything comes off, including the engine bay, the interior and the underside if you can. Then take a few shots during the work and a clean set of the finished result. Dated photos let you match a part to the day it went on. If your phone stores the date, that is enough.
Keep the numbers and the paper
- Dyno sheets and test results. Note whether power is at the wheels or the crank, and what the car was running on the day.
- Alignment printouts and tune details. Write down the tune version or the date, so you know which one is current.
- Itemized receipts. A card statement shows a total, not what you bought. Keep the invoice or take a photo of it.
- Maintenance. Oil changes and fluid services belong in the same place as the upgrades.
Keep one folder for all of it and one backup copy in the cloud, so a lost phone does not take the whole history with it.
Update it after every change
The list only holds up if it stays current. Add the row the day the part goes on, while you still have the box. A five minute habit after each change is easier than a weekend of catching up before a show or a sale.
Keep private things private
If the list will be public, leave out your VIN, your plate and your address. Decide whether you want the build cost visible at all. On a BuildTags build page the cost stays hidden unless you choose to show it, and you can set the page to public, unlisted or private.
Turn the list into a page people can scan
A spreadsheet is a good record and a poor thing to show a stranger. A build page puts the same list, the photos, the power numbers and your socials into something that reads well on a phone, with links to where each part is sold. Add a QR decal to the car and anyone can open it with a camera. Read the QR code stickers guide for placement and scanning tips, the car show guide for display cards, or see how BuildTags works.
Put it on your build
One page. One permanent QR.
Make your build page for free, then tag the car, bike or truck with a QR decal that opens it. Change the page whenever the build changes and the sticker keeps working.