programmatically access car dealers inventory

AutoTrader gets its data by

1. Dealer manually adding the vehicles
2. Dealers third party services pushing the data to AutoTrader nightly (FTP or Emailed) from services like.
   • website providers / inventory management tools such as AutoJini.com, VinSolutions (now owned by ATC)
   • Lot management companies such as Dealer Specialties, KBB CDMData (these companies come to the dealers lot and take the pictures and then send the data out to website providers, classifieds sites etc.
   • feed processing company like Digital Motor Works.
3. or AutoTrader is pulling the data from the Dealer Management System like (Reynolds & Reynolds, ADP, Arkona, etc) pull method is mostly used for new cars.

Inventory is normally not accessible by other third parties... however one can always get the data for most dealers in the US via API from Oddle or Vast and Edmunds.

I should also add that you can get a custom crawl of all the data on ATC & cars.com from 80legs.com. This kind of service is used by companies that do pricing analytic for dealers.

You can also try contacting the website providers or the lot management companies and get the data feed from them.

There are an ISO 3779 (Europe) and FMVSS 115 (US & Canada) standards for all the cars on the market.

Each and everycar is identified by a VIN (Vehicule Identification Number).

I think that is what you are looking for.

You can get the official well-updated VIN data here

If you want to find it another way, google as usual will be your friend.

You can pull dealers inventory (active and historical) using Marketcheck Cars API

You can use Marketcheck Dealer ID or the source website domain for the dealer you are looking to pull the inventory.

Pull active inventory by dealer ID - http://api.marketcheck.com/v1/search?api_key={your_api_key}&dealer_id={dealer_id}

Pull active inventory by dealer source website - http://api.marketcheck.com/v1/search?api_key={your_api_key}&source=www.sanleandrohonda.com

More cases documented at the official API documentation

You can sign up at the developer portal hosted here and obtain the API key to start evaluating the API.