I suppose it would depend on the condition of the car, if it is ding and dent free with excellent interior (clean no burns rips or scratches, I wouldn't trade it in for less than 14G and you may even get up to 16 if you work them really good, you can aproach the sale from 2 ways, one you get a great price <msrp and get low trade in or you can try and maximize your trade in and pay a little more for the car, work the deal from both ends and you won't be dissapointed. The ideal would be high trade in and low purchase price. But you got to win one of the two if you can't get one side to favor you, keep shopping.
Good Luck!