Just a couple of hints, Get pre-approved at a bank or Credit Union for a "New Car Loan" usually a lower rate. When negotiating at the dealer do NOT negotiate based on payment, If they ask if you are financng tell them NO, You are paying CASH, gives you more leverage, If they ask about a trade say NO, bring that up after you get the best price. Go to the dealer during the last three days of the month, much more incentive for them to sell and make quota, they also can get additional rebate incentives from the manufacturer at the very end of the month to move inventory. Do your homework, The dealer will know ALL the rebates and incentives available and if you don't they will still apply for them and keep them as commission. Don't bring anyone else with you, no wife or kids. Go at the end of the day so you are there when they close and be prepared to walk out, they won't let you
After you negotiate your best deal tell them you have to sleep on it, do not leave a deposit. If you have a trade show up with it the next morning and tell them you changed your mind and you do want to trade in the old car and you know exactly what you need to get for it, this may take a while because they will be upset, they REALLY hate this tactic but it works GREAT!! Make sure you know the book value of your trade and if you can have the check from the bank in hand made out for the price you negotiated MINUS what you want for the trade and then pull the walkout routine you will usually get what you want. If you need a lienholder and the P&S ahead of time this may not be an option. The most important thing is to know what you want and what the dealer paid and what the true value of your trade is worth. You should be able to get almost any car at or below dealer cost. I always have. It's a little work but it's fun and you can save thousands of dollars but you won't make any friends!