One trick with dealers is to never mention a trade in until you're almost at the end(or defer discussions about it). That way you leave open the option to leave

One trick with dealers is to never mention a trade in until you're almost at the end(or defer discussions about it). That way you leave open the option to leave the trade-in out of the deal and force them to give you a number without it factored it. Also, never do the 4-box and have your financing sorted out up-front if you're not doing cash. Any chance they get to adjust more than one number is when they'll adjust the terms in their favor.