Should you visit dealers to shop for a car?
This is all great advice, but here's the thing: car dealers spend their lives coming up with ways to sell the most cars for the most possible. If you're looking to buy a car, there's a good chance that you've read only a couple magazine pieces, if that, about how to avoid getting taken. Car dealers are like a mutating virus: find out one way to beat them and they'll come up with others, and they have all the time in the world to dream them up.
My advice: try to do the bulk of your shopping online, and only visit the lot to test-drive a specific car that you've called about -- and make it clear that you don't want to try something else. If they had something else you wanted, it would have shown up in your online search, right? I'm sure plenty of people will disagree with me but I think that your odds of overspending on a car increase if you start test-driving stuff that the dealer -- who doesn't know your budget and wants to make as much money as possible -- suggests.