MarketCheck Compass Detailed Auto Inventory Data

Overview

Daily VIN-level records of vehicles listed for sale on North American dealership websites. Each record describes one vehicle on one calendar day it was available, with 39 fields covering vehicle identity, mileage, pricing, days on market, seller identity (including mapped stock ticker symbols for publicly traded dealership groups), and geography. Both new and used vehicles are included. The daily-panel structure supports measurement of inventory levels, days-on-market dynamics, listing-price changes, and inventory composition at the vehicle, dealer, dealership-group, brand, or market level.

MarketCheck crawls dealership websites across North America every day and structures the results into VIN-level data on vehicle listings, inventory, sales, and pricing. Its collection covers more than 100,000 dealer websites and observes roughly 6 million unique VINs per day.

Data Description

One row per vehicle per calendar day it was listed for sale, keyed by pseudo_vin and calendar_date — approximately 13.2 billion rows spanning January 2017 through early July 2026 as of the initial delivery.

Coverage

United States and Canada, 2017 to the present. Coverage spans 100% of franchise new-car dealers and 92% of independent used-car dealers. Four categories of vehicles are not captured: (1) vehicles from OEMs that sell without dealer networks (e.g., Tesla, Rivian, Lucid), which appear only when resold as used vehicles; (2) fleet vehicles, which are not posted on the web until resale; (3) custom factory-direct sales, likewise captured only at resale; and (4) small independent dealers without websites, roughly 8% of independent dealers.

Methodology

Web-scraped daily from franchise and independent dealership websites in the United States and Canada. Vehicle identification numbers are pseudonymized as an MD5 hash (pseudo_vin). The provider maintains the data in a compact change-log form, in which a vehicle appears only on dates a listing attribute changed, and expands it into the full daily time series delivered here; days between observed changes carry the most recent value forward and are flagged (is_ffilled). Provider quality assurance removes implausible rows (odometer readings above 500,000 miles, days on market above 730, prices above $500,000 outside the super-luxury category) and imputes sparse powertrain, drivetrain, and fuel-type nulls from the modal value of matching vehicle cohorts; remaining nulls (under 0.1%, concentrated in discontinued makes) are left in place. Combustion-vehicle fuel-economy outliers are replaced with cohort modes.

Additional Notes

Days on market (dom_active) legitimately resets when a vehicle is relisted. The companion MarketCheck Compass Detailed Auto Sales Data dataset records the corresponding sale events, inferred when a vehicle leaves this inventory panel.