RS auto trade
there's no way you're going to get anywhere close to 14 in trade. Especially with damage. Keep in mind that with current incentives, a brand new base 2.5RS 2005 can be had in the high $15- low 16's range.
That said, you should be able to to a bit better on the vehicle you're picking up.
I would think that $5000 trade difference would be an attainable offer in your situation.
You could consider selling or buying private party, but then you undertake all the work yourself, and don't have any backing on the new car. If you did a private buy and a private sell, you'd probably only have to spend around $3,000-$3500, since it's pretty easy to get a 50K mile WRX in the $15,000 range.