There are shelters for transitory housing that will help him get stable.

Lots of assistance available. He can call 211 and get help.

The only reason to be homeless in this country is by apathy. If he is pro-active about his life, there are social services in place through the VA and the state of Arizona.

Start here: http://www.cir.org

Can he afford plates and insurance? If not, giving him a car is not a sustainable way of helping. Finding a shelter and learning a bus schedule is.

As a social worker, I firmly believe that with effort, EVERY human has a chance in this country. As a veteran he has extra resources. The best way to help someone is to show them how to help themselves.