Yes, unfortunately, instead of GM rising to the level of Saturn, Saturn sank to the level of GM and became just another Oldsmobile.
Not really. If you order online, the dealer still gets final say. If you go to a dealer, the add a line somewhere in the contract saying 'subject to dealer markup' or 'plus dealer charges,' etc. Even in the case linked above where the man got a confirmation printout from the Ford dealer the dealer refused to honor it.
As a practical matter, even if you attempt to force the dealer to honor a contract, you have to file suit. in the mean time, the dealer has sold the car so even if you win your case they don't have a car to sell you.
When you order a car from Tesla, the order price is the final price and they honor it. They may raise the price next week, but the price of the car you ordered stays the same. Tesla is raising prices to match supply and demand, but they are doing it in an honest, transparent way. So no, it's not the same at all.