After they started charging for car ads Craigslist in Phoenix had maybe a page and a half a days worth of ads. It seems to be coming back up though and now is probably at least back to half of what it was. I save interesting ads on CL, Marketplace and Offer up and it seems CL sells the most cars. If I really want to sell a car I'll pony up the $5 and put it on Craigslist along with the free sites.