I think it depends on what kind of vehicle you donate. The IRS allows you to donate the vehicle for its aPpraised value. I’m not sure how they come up with a fair market price for autos, but I knew a guy who donated a back hoe to some organization and got a bit more than fir value for it. In any case, a letter from someone familiar with selling what you are donating usually suffices, unless you get into exotic stuff.
A few years ago, realizing I’m getting old, I donated a real nice basic trainer airplane (C-150) to Bis State College/Bis high for their aviation training program. It now gives me a good feeling to see it flying over our place on downwind for runway 31 at Bis. Beginning to turn out future airline pilots and at least one Air Force pilot in training!
That’s beside the point, but there are special rules to donate something “different” like an airplane. Took me over two years to do it. The IRS required an appraisal from a “professionally trained aircraft appraiser” to establish a fair market value for it! Fair enough but where in this area can you find one? I had letters from several aircraft sellers around the country pretty well all agreeing on a fair market value, but IRS wouldn’t accept any or all. After a few years we finally got an OK to be a good citizen but had to do it in a roundabout way. A real PITA but finally got it done.
Best thing is to consult with your accountant. Anything unusual you may have to be prepared for fees from accountants, attorneys, appraisers,etc. but autos I believe are straight forward.
As Allen says, you probably don’t come out financially too much (depends on your income etc) but to donate something to some IRS approved organization that they really need or can really use, gives you a bit of a good feeling.