Methodology
Bounded live queries plus reviewed bulk-import projections, one exact identity, and a documented separation between zero evidence, unavailable evidence and an official safety action.
The make, model and model year are checked against NHTSA vPIC (GetModelsForMakeYear). A model matches only when its official vPIC name matches your input exactly once punctuation, spacing and capitalisation are ignored. No badge is guessed, no alias is bridged and no manufacturer ownership is inferred from the make name.
NHTSA recallsByVehicle is queried for that literal make, model and model year. Every campaign returned is published in full: NHTSA campaign number, component, report-received date, summary, consequence, remedy and NHTSA's do-not-drive or park-outside flags, each linked to the official campaign page.
NHTSA complaintsByVehicle supplies the complaint total, the counts of reports mentioning a crash, a fire, an injury or a death, and the six most frequently named component labels. Complaint narrative text and VIN fragments are never published, and the JSON response carries at most five recent records.
The approved NHTSA ODI investigations flat-file import is matched to the same punctuation-insensitive exact make, model and model-year key. Action number, component, subject, opened/closed dates and an associated campaign number are retained; long narrative summaries are omitted. An opened investigation is not a defect finding, and a closed one is not vehicle clearance.
FuelEconomy.gov is asked for the model menu, then up to eight matching model names, then up to twenty-four configuration records. Those records are collapsed into ranges (city, highway, combined, annual fuel cost, CO2, engine displacement, cylinders, electric range) and into distinct sets of vehicle classes, fuel types, drives and transmissions. When more variants exist than the bounded view covers, the page says so.
NHTSA can answer an exact search with HTTP 400 while still reporting a successful, genuinely empty result. That specific payload shape is the only one treated as a verified empty source response: the status is 400, the message reports that results were returned successfully, the count is zero, and the results array is present and empty. Any other non-success response is reported as unavailable rather than as zero. A verified empty recall result means the queried source returned no matching model-level campaign at that moment. It is not safety clearance for the vehicle.
Complaint counts are raw report volumes. They rise with sales volume, vehicle age, mileage, media attention and the willingness of owners to file. Turning them into a rating would need validated vehicle-population denominators, age normalisation and a method that could be independently reproduced. None of those exist here, so ModelYearFacts publishes the separate evidence blocks and lets the reader compare like-for-like model years instead.
US dossiers still query official NHTSA and EPA APIs for bounded campaign details, complaint incident fields, identity and configurations. Cross-model search, complaint matrices, recall counts and investigation records use compact reviewed projections generated from the approved imported flat files; each page shows its projection timestamp and links the exact object register. Raw R2 is never bound to the public request path. UK MOT hubs separately ship a compact derived snapshot (make×model aggregates with a 500-test minimum), not live per-test queries and not the 109 million raw MOT rows.
The CPSC page selects only notices whose public heading or product name contains an explicit child-passenger, charging, lifting, tyre-care, towing, carrying or in-vehicle accessory term. It does not fuzzy-match long descriptions and does not join a consumer product to a make, model, year or VIN. CPSC remedy and company status can change, so the official notice always controls.
US model-year files are gated on the EPA FuelEconomy.gov catalogue of vehicles sold in the US, which runs from 1984 to 2027 and yields 10,603 dossiers. UK MOT hubs use a separate gate: the compact derived MOT summary, min 500 tests, one URL per canonical make×model slug.