International warehouse shopping chain Costco includes functionality in their tire department website to enter a vehicle's license plate number to automatically determine the vehicle's make and model.
What data sources are they using? Are there any open data sources?
I suppose they could be using http://www.vehicleregistrationapi.com, but that service charges $0.18USD per lookup in bulk. I somehow doubt Costco is paying a third-party company every time a potential customer performs a lookup on their website.