Only veterans and service members suffering from certain disabilities as a result of their service are able to claim a government grant toward buying a car. Most government grants are available only to institutions, such as universities or non-profit organizations, or to specific research projects, rather than individuals.
The grants available to individuals are generally referred to as "personal grants" or "benefits." While a person may not qualify for a grant specifically for the purchase of a vehicle, it is possible he might be entitled to other benefits. The easiest way to check is to fill in the questionnaire located on the government's benefits website.
Disabled veterans and service members may qualify for a grant from the Department of Veterans Affairs, or VA. The VA can provide a one-time grant of $18,900 to those qualify, as well as the cost of installing and maintaining any necessary adaptive equipment throughout the course of their lives.