Don't use ebay, their fees can be quite high. Try putting a sign in the window, if your town allows that (the city I live in actually prohibits that!), use www.craigslist.org, or try placing an ad in a local car sales magazine that you can usually find at gas stations. Also, if none of those work and you're running out of time, many car dealerships will buy a car directly from you, even if you're not buying one from them, especially if it's in very good condition.