Summarize:

Not all charitable contributions are tax deductible—the donation has to go to a qualifying charity or nonprofit. Usually, 501(c)3 charities and religious organizations will qualify.  In order to double check, go to https://www.irs.gov/charities-non-profits/exempt-organizations-select-check to look at the IRS’ listing of exempt organizations.  Remember though, churches are usually not listed in the directory.  The only time a charitable organization won't be listed is if it a religious organization or a subsidiary of a larger charitable organization. In that case, if the larger organization is listed, you can be sure the subsidiary is as well. Not all charities accept cars as donations, so be sure to check before you drop your car off. If you can't find a charity you'd like to donate your car to, Car Angel uses car donations to fund a variety of projects, including literacy, children's welfare, and prison outreach. Learn more at https://www.carangel.com/programs.php. For an alternative, Car Donation Wizard takes care of a lot of the intervening steps for you. You just pick an affiliated charity, fill out a form, and schedule a pickup. Find out more at https://www.cardonationwizard.com/. Although the IRS' listing of exempt organizations should be all you need to find a reputable charity, if you still have doubts, then ask to see the organization's 501(c)3 certification from the IRS, and their articles of incorporation and bylaws specifying that they accept cars as donations.  You should also beware of charities with excessive administrative costs, which include salaries, offices, and office supplies. Charity Navigator, an independent nonprofit organization, actually evaluates charities for their financial health and levels of giving relative to donations. You can learn more at http://www.charitynavigator.org/. Make sure the person who accepts your donation is affiliated with the charity.
Choose a qualifying charity. Make sure the charity accepts cars as donations. Beware of scams.