I know people that have eventually realize they don't know what they are doing so they let their credit union or bank negotiate the car to get the best price to avoid the hassle.
The bank has no interest in helping you get a deal and will negotiate for the sake of getting the car at your expense to make money from you. People are so gullible and that's why you can never get a deal but what's worse is knowing you fine for an acceptable loss and the dealer still plays games.
I think you said it best that it is much wiser to keep your car long as you can.
This is one of the few industries that is still run like a third world roadside cart.

 

The whole experience of buying a car, is for the most part terrible. I love this new thing they do now...hit you with $500-$700 dollars worth of paper work fees AFTER you negotiate the price. Makes me laugh, it really does.

Consumers have more options now, no longer do you have to walk into a place blind. In seconds you can find out just what the vehicle you're interested in is going for in your area. It's simple and it's quick. It also gives you knowledge and leverage. Just be careful of the "finance" managers and dealer "fees". That's where they get you. And the warranties (they make a commission off of those too). And I love hearing people say, yeah but they have me ______ for my trade in!! No, they screwed you even harder than you possibly could have imagined.