Chuck, it sounds to me like it is the principle more than the money that is leading you to consider cancelling the order. If you will always feel like you were screwed on the deal, it will tarnish the ownership experience a little bit.
Axel had great advice about joining a credit union, which is usually pretty easy to do.
If that is not an option, maybe a manager can do something to meet you halfway. "So sorry, Mr. Chuck, the government made GMAC take over Chrysler Financial, so they can't give you the deal that they had been offering, please select $500 worth of dealer accessories for your new car, and we will give them to you on the house." Or something like that.
If you can get enough of a gesture from them to make you feel respected, take the deal because you're getting the car well below MSRP, and probably not far from invoice.