You actually have more bargaining leverage with new cars than used (imo). With a new car you can find the invoice price of the vehicle you want. This is the price that the factory sells the vehicle to all dealerships. This at least gives you a starting point. You know that the dealership will not go below this price since they will not make any money. There are a few exceptions to this where there are other factors or deals that make the dealership money so that they can go below the invoice price on the vehicle but are making more money some where else. This is fairly rare and not usually something that you can control. If you know the invoice price then you can decide how much you are willing to pay the dealership for that vehicle.
Though you have more bargaining leverage with new cars, you can generally get better deals with used cars, you just don't know what the dealership bought it for. There are tools like kbb (Kelly blue book) that will give you pricing for wholesale values of vehicles but it's no guarantee that the dealership actually bought it for that price. If the car was a trade in then they could have bought it way lower than that price depending on how well they worked over that person in their deal. When I was a car salesman I sold way more new cars but made way more money off of my used car deals. I think I was always pretty fair with people (part of the reason I'm not a car salesman any more) but used cars generally have more margin.
Though you have more bargaining leverage with new cars, you can generally get better deals with used cars, you just don't know what the dealership bought it for. There are tools like kbb (Kelly blue book) that will give you pricing for wholesale values of vehicles but it's no guarantee that the dealership actually bought it for that price. If the car was a trade in then they could have bought it way lower than that price depending on how well they worked over that person in their deal. When I was a car salesman I sold way more new cars but made way more money off of my used car deals. I think I was always pretty fair with people (part of the reason I'm not a car salesman any more) but used cars generally have more margin.