People donate because they are emotionally invested, have empathised or because they cannot say no. It doesn't only make other people happy, it also makes you happy knowing you did something good for the community.
With so many worthy causes vying for your dollar, choose one or two that are near and dear to your heart. Angel Ministries started accepting vehicle donations to aid their cause. That cause includes funding several of their own projects, including prison outreach/rehabilitation, children's moral DVD outreach, worldwide leadership training, and child support for children in third world countries. I would love donating my car in the future because right now I can't afford to buy a new one. Anyway, currently the Angel Ministries organization support a bible training camp and soccer camp in Sudan, street and church outreaches to children and teens in Lima, Peru and Pemba Mozambique, Africa. Please check their website (carangel.org) for details on how to donate your unused old car.