As in using one to paint a Jeep? Not unless you plan on using house paint!

Automotive finishes require adequate atomization of the paint. Typically a 1.3 to 1.6 spray tip. Automotive paint is much thinner than house and wall paint, and if you try to spray it with a Wagner, without going into alot detail, you will make a mess!

If you don't have access to automotive spray equipment, and you really want to do it yourself, I have seen some pretty fair paint jobs done with rattle cans. Time consuming, and hard on the index finger, but possible.
If you mean you have one for sale, you should repost in the classified section.