A car dealer is a retailer. In the absence of a contractual agreement with the manufacturer or distributer, a retailer can charge whatever they like for the things they sell. One of the inherent problems with a free-market economy is that people with more money get the scarce commodities and people without money don't. A free market sets prices as sellers adjust their prices to what their customers will pay. The problem is not that some car dealers are scumbags. The problem is the extreme disparities of wealth that allow some people to jump to the head of the line by paying a premium while leaving others without the basic necessities of life.
Car dealers have always set their prices above or below MSRP according to the demand and the negotiating skills of the buyer. This is nothing new. Fixed pricing is one of the things I like about Tesla.
You say: "...the price increase should have a limit for a depreciating assets like a car."
There is a limit: It's what people will pay. If you want the government to set a limit, that's a can of worms. And if you want Ford to impose a limit on its dealerships, well, Ford knows what the dealerships are doing and if they do nothing about it, then they're apparently happy with it. Bottom line: you set the limit on what you will pay. In the case of cars, there are always other cars, and other dealerships. Don't buy from scumbags. I don't. (In around 1986 I was deciding between a Honda and a Toyota. I ended up getting the Honda because the Toyota dealer was an a-hole.)