Ask for one number, in writing
The out-the-door price is the total you'll pay to drive away — vehicle price, fees, and taxes combined. Ask for it in writing early, and refuse to negotiate against a fragmented quote where price, trade-in, and financing are shuffled around to hide where your money is going.
When everything is collapsed into one figure, the classic tactics lose their grip. A discount on the sticker means nothing if it reappears as a mystery fee three lines down.
Separate the trade-in from the purchase
Bundling your trade-in into the deal gives the dealer room to give with one hand and take with the other. Settle the purchase price first as if you had no trade, then negotiate the trade-in value as its own conversation. Know your car's independent market value before you arrive.
If the two are tangled together, untangle them. You're entitled to see each number on its own, and any reluctance to show them separately is itself useful information.
Be ready to leave
The strongest position in any negotiation is a genuine willingness to walk away. Have a target out-the-door number, a second listing you'd be happy with, and no emotional attachment to one specific car. Politeness and patience beat pressure every time.
Most of the value in a negotiation is captured before you ever sit down, by knowing your numbers and your alternatives. The conversation itself is just confirming what you already decided.