In this day of information, if you get "scammed" it's your fault. Anyone can go on the net and see every dealers inventory and the specs on the car your looking at. There are hundreds of sites that a person can use to do research on the vehicles they might be interested in. Get your own financing, and the dealer has no chance to back load your deal. Show up prepared, and the dealer will treat you with respect. If they don't walk away, and find one that does.
My neighbor had a Chrysler Pacifica. When the lease was up, she went to the dealer and asked to see a vehicle that "excited" her. two hours later, she was home in a brand new Jeep Commander. If I could get three people a week like her, I'd be selling cars right now. People like her are easy prey, and I don't blame the dealer at all for taking advantage of her ignorance.