I sent you a private message about dealers near you. Check your forum Inbox.
A trade in would make it harder (at least for me) to negotiate price. Unless it's a relatively young car, most new car dealers will sell a trade-in wholesale, meaning that they know that they can't ask a lot for it, so they won't want to give you a lot for it. As a general rule, you're better off selling the trade-in yourself, if you can do that. (This is harder to do if you still owe financing on it, or if you are uncomfortable dealing with people that respond to a classified ad on Craigslist, Facebook, or what-have-you).
If you didn't have a trade in to complicate the negotiations, then my suggestion would be to figure out what you want to pay, figure out what is your walk-away price, and then contact the dealer and tell them: "this is what I'm willing to pay and if you can agree to it, I'll be in tomorrow to sign the paperwork. And by the way, my FICO score is excellent: according to a recent statement from my credit card provider, it is (whatever it is. Obviously, if it's not a superlative score, leave this statement out. But include this information if you have a good score, even if you are paying cash, because it will impress the dealer that you are more likely to be a reliable customer that will close the deal)".
When negotiating like this, it helps if you can have the courage of conviction: if you know that you actually will cool your jets (for at least a week) if they don't agree to your price. Even if that means that maybe they sell your dream car to someone else in the interim (but probably they won't... but they might). If you know that you won't jump until they meet your price, you're likely to telegraph that attitude to them (and if you feel like you actually will cave in quickly if they don't agree to your terms, you're likely to telegraph that attitude to them to).
Sales were down last year, and are probably even worse right now, so dealers are likely to be highly motivated. They just need to be persuaded that you are proposing a deal that will actually happen, soon, and at a price that, while not of their dreams, is sufficient to make them happy and profitable.
I took this approach with four dealers. Two were flexible, two were not. One of the two that was flexible sold a car to me. The two that were not flexible wound up with stale inventory on their lots that started to not look so attractive to prospective buyers when the new model year started coming out.
You can take a similar approach with a trade-in, but it makes things more complicated. Go to something like KellyBlueBook.com to estimate the value of your trade-in. Be sure to look at the trade-in price, not the private-sale price. Try to be honest when estimating the condition of your car (almost nobody has a trade-in that is in "excellent" condition). Negotiate with your dealer for the new car at first as if there was no trade-in involved in the transaction. Once you've got a price based on no-trade in, tell them that you were thinking of selling your old car on Craigslist, but you would like to know how much they would give you for it if you traded it in instead. Taking that two step approach is likely to make it easier to negotiate, and likely to make it easier for you to understand how much the dealer is really offering you for your trade in.
Good luck!