Selling my GP

I am selling my Black 06' Grand Prix. I am in school and am running tight on money between, car payments, insurance (2 tickets) and paying for my schooling. I am asking $18,000 since that is about what i have left. The car was purchased in July of 05' brand new. It has 6500 miles and @ 3100 i changed it to synthetic. No scratches, always clean, and never beat on. No mods either. I would be interestead in a trade & money but something cheap maybe 3-4 thousand and then you pay the rest on the car. Im located on the southside of Chicago in suburb, Alsip. Thank you.