The details and current status of data requests submitted through the Data Request Help Desk page can be seen here.
List of registered vehicles. Make and year of cars registered. Ideally federally, but state level data would be amazing as well. No names of vehicle owners or license plate numbers needed.
Data.gov is a catalog of datasets provided by U.S. Government agencies in accordance with the Open Data Policy. While some state and local governments make available their data through Data.gov, Data.gov mainly offers datasets from federal agencies. Please connect with state open data offices, sites, or Department of Motor Vehicles for the information you seek.