When looking for a new car, there are few ideas you should follow to get the best deal that you can.
Negotiating with a dealer can be tricky, they do this for a living and are well used to getting people to agree to something they didn't want 5 minutes earlier. You need be strong and assertive, let them know that you have seen cars in other lots and aren't bothered which one you get, you will go with dealer which offers the best deal.
Be succinct and business like at all times. Salesmen/women rely on being able to chat to you as if they were your friend and talk you into buying something way out of your price range. Stay remote and seem uninterested in their patter until they give up and start to talk about the car.
The main reason that salespeople chat about everything under the sun is to get you to drop your guard and let them manipulate you. They are good at their job and know instinctively when to strike. If you like and trust someone you are easier to talk into things.
Walk into that lot with an air of someone who knows their stuff. Check out the value of the car with Kelly Blue Book and jot that down too.
Another good idea is to find out what others have paid or cars at that lot and what terms they were given. This gives you a great bargaining point when it comes down to the nitty gritty of thrashing out the final deal.
The salesman relies on customers buying cars from them to pay their bills and feed their families, it doesn't hurt to remind them of this fact of they overstep the mark and start getting pushy.
Knowing exactly what you want before you enter the lot will make the sales man uneasy. He will still try and undermine your confidence and talk you into something that you don't want. If the dynamics shifty and you start to feel undermined, walk out straight away.