There was a news story last year and I think it was Chevy. They were going to raise their sticker prices so they could offer larger discounts to fool the gullible buyers who like to brag about how much they talked the dealer down.
Anyway, I agree with Turbo, offer them $42,500 all they can do is say no. If they won't come down enough on the price, try for something else like free oil changes for three years. Or if it has winter tires on it, see if they'll put a set of summer tires on it and of course you keep the winter tires. On things like oil and tires they have a lot of markup on them, so they'll sometimes use them for bartering.
Let us know how you came out.
Bill