So the people who dont know better pay for stuff they dont need? Sounds like literally everything else. Most people who buys cars dont know anything about cars and thus they likely overpay. This sucks but its in fact a "free market" thing.

A free market, according to my econ prof at least, has:

1. easy entrance/exit to the market,

2. many buyers and sellers, and

3. perfect information availability.

If the players don't have good information, it is at best a severely degraded free market.

All the infos about cars are easily available. It chances nothing, most buyers of car simply dont care enough to get fundamental knowledge about cars. If you would value the time it takes for an average car buyer to get fundamental knowledge it would cost way more than what they overpay so unless you already have above average knowledge it makes no sense to dig into it. You are better off asking someone who has the knowledge and no incentive to fool you aka a friend not the sale person.