I R S laws have changed , you no longer get to value the donation at average retail . The value will be what amount that the non-profit receives , of which you will get a tax value based on your tax percentage .
Understand that in most states your charity CAN NOT take title and pass it to the buyer as these non-profits are not auto dealers . There is a middleman who tows it , transfers the title , sells the auto and gets MOST of the money ! Your non-profit can not take title because they can not issue a title or collect sales tax and are not insured . I only know of one non-profit in Florida who is a licensed dealer , most will go thru a company licensed as a auto dealer .
The non-profit gets very little of the money . Much better to sell it yourself and then decide what to do with the money .I worked for over thirty years for a company that provided this service and I was always surprised at how little the non-profit got .