FYI, used car salesmen > new car salesmen because the affiliated dealers have a monopoly from the manufacturer and laws to prevent competition, whereas used car lots don't have these advantages and have to survive in a much more competitive environment. I know honest used car salesmen and have dealt with them. It's also more about the sales manager than the salesman working the floor, who actually has very little power with respect to pricing and mostly just follows a script and does logistics.

Also, the used car market is much more efficient than the new car market. You are a lot less likely to get ripped off, believe it or not, when you buy used. It is also three times as large as the new car market, with much lower barriers to entry and no manufacturers carving up sales regions and limiting dealer franchises in each region, and penalizing vendors that sell outside their region, e.g. creating little local monopolies. Every used car dealer has to compete with carmax and carvana and hundreds of other used car dealers that have access to the same pool of buyers and sellers. They have to fight for those buyers and sellers. That's a very different situation than the four Toyota dealers in your metro. In fact the reason why Toyota dealers are especially bad in terms of ripping people off is because the Toyota product is so good and you have to go to them to get a new Toyota. But if you want a used Toyota, suddenly have 10x the options, and not one of them has a monopoly from the manufacturer.

Not saying there aren't bad apples in used car sales, but it's a lot harder to survive long term on shady practices than if you are backed by a major manufacturer, have exclusive access to sell their cars, and also exclusive access to do recall and warranty repair. Those types of monopolies can prop up all sorts of bad practices.

Oh, now there is an idea for an app... how to bs your used car salesman right back.