I would get a quote from Carmax and compare it to Kelly Blue Book. Assuming a significant difference, I would try selling it myself. Suggestions:
1. Buff and detail the daylights out of the car. Shine, shine, shine, scrub, scrub, armour all, etc. Put premium gas in it
for a tad of extra spunk at the test drive. Fix anything and everything cosmetic.
2. Put a sign in the window of the car with the price (none of this "best offer" stuff...people will waste your time) and your phone number. If you can, park it in a busy location.
3. List it on Craigslist with the price (close to what you would take). Somewhere between Carmax price and full retail.
4. Close the deal at the buyer's bank. This way, there will be no concern the cash or cashier's check is phony.