your not going to find an 08 under $18k bud, these cars hold their value. Maybe you should go little older, that body style is terrible anyways. Also it was the worst year Subaru made the WRX. The turbo is diff, the interior is a lot cheaper looking, and the extra body lip kit was not included unless you got a limited.
DiRty Impreza, I found a private seller who has a 2008 WRX with 40k miles that is selling for $17,500. No accidents, clean title, he is the second owner, has receipts and has done the scheduled tune ups. Do you think this is a good deal?