As Shane points out, you're better off being transparent with the dealer, up front. We expect the same from them, so it's only fair that we, as consumers, do the same. Wasting a bunch of their time by trying to play the Partner Program card late in the game would annoy the hell out of me, and probably you too, if you were the dealership. Put your cards on the table, make a reasonable offer, and then move forward from there. Likely to result in a better outcome, more quickly, for both parties.
Next weekend is the last weekend of the month. Between that fact and how late it is in the model year, it should be a great opportunity to make a killer deal on an in-stock car.