Bottom line is that they want to sell the car, go and test drive it, act like you want it. Don't make them think that you can't live without it, because then they won't really work with you. Let them take your phone number and go through the steps of them appraising your car, then walk away. Even if they give you a deal that you would really consider, still walk away. Like I said, they WANT to sell the car, they will almost always call you back with an even better deal if you walk out. Also, take your car to one or two other dealerships and test drive a car for the hell of it, see what they will give you for a trade then you will have some leverage.
When we traded in our 2002 *-10 Z-r2, the first dealerships offer for trade was only $6,500! (these trucks are selling for around $12,000 right now) The second dealers FIRST offer for trade was $9,000! We ended up pushing them a little more and also got the back bumper repaired (on the vehicle we bought) after they said that they were not going to.
Two days after we left the first dealer, they called me and basically BEGGED me to come in and trade the truck in, they offered me more money and also money off of the car we test drove.
You could also find another SSEi from another dealer, see what deal they will work out with you. Take that car on a test drive over to the other dealer and tell them the deal the first dealer wants to give you. Make them fight for your money, otherwise they will walk all over you.
I can guarantee that you can get a lot better deal if you haggle them and DON"T give in untill you are satisfied.