Methodology
Every number on buycars.fyi comes from a buyer who reported the car they bought. A number appears only once 5 deals back it, and it always says which cars it covers. Deal counts are never shown.
Where the data comes from
Buyers add their own deal: the VIN, when and where they bought, new or used, cash, finance or lease, and what they paid. Adding a deal unlocks every price on the site.
Car details come from public sources, refreshed monthly: the NHTSA vehicle database (vPIC) for makes, models, trims and VIN decoding, EPA fuel economy data for engine and drivetrain variants, NHTSA recalls, complaints and safety ratings, and US Census ZIP code files for states and metro areas.
How a deal is checked
- The VIN must pass its check digit and decode in the NHTSA database. The decoded make, model and year are used, not what the buyer typed.
- A car with more than 1,000 miles, or one already sold before, counts as used even if reported as new.
- The same sale reported twice is held, not counted. Each later sale of the same VIN joins that car's history, like a house sale record.
- A price more than 3 median absolute deviations from similar deals is held for review rather than published.
- Each person and connection can add a few deals a day, which limits spam.
Prices are reported by buyers. They are not yet checked against purchase documents.
How numbers are summarized
Each headline number is a median over the last 24 months, kept separate for new purchases, used purchases, new leases and used leases. New purchases show percent off sticker (MSRP), used purchases show the selling price, and leases show the monthly payment.
When the exact car has fewer than 5 deals, the number rolls up one level at a time until it reaches 5:
| Level | Covers |
|---|---|
| 1. Trim | The exact trim and model year, for example 2023 Santa Fe SEL |
| 2. Model year | Every trim of that model year |
| 3. Nearby years | The model, one year either side |
| 4. Brand and body | The brand's cars of the same body type, for example Hyundai SUVs |
| 5. Body | Every brand's cars of that body type |
When no level reaches 5, the page shows no price. If buyers of that model year have reported new purchases, it says only whether they paid below, near or above sticker.
A state's number is used when that state has enough deals; otherwise the number is national, and the page says so.
What stays private
| VIN | Stored only as a keyed hash. Never shown, never sent to analytics. |
|---|---|
| Dealer name | Kept for our checks. Pages show the state and metro area only. |
| ZIP code | Used to find the state and metro area. Never shown. |
| Only if you ask to be told when prices are ready. One email per car. | |
| Loan APR | Kept for our analysis. Never published. |
| Mileage | Shown exactly under 1,000 miles, rounded to the nearest 1,000 above that. |
Below 5deals, you see only your own deal, never anyone else's. There are no accounts.
Bought a car recently? Add your deal