Used car dealerships run scams, too. I've bought a lot of cars, though, and never from a dealer. Some folks act as if they're OBLIGATED to buy a new car every couple of years, and obligated to put up with these people.
dealerships are the reason I've only ever owned 3 cars in over 20 years of driving. My last car was a mitsubishi bought from a Chevy dealership, I think I got reamed on that one. My current car is a Toyota from a no-haggle dealership. Went there, they brought up Edmunds.com "true car value," we walked through it together, and they knocked $1000 off that price. I walked away happy. And that Toyota has been going on 6 years now. The only major service it's needed was to clean out a nest that some pack rats created in the engine bay (before chewing some spark plug wires and electrocuting themselves)