This is a huge problem in the Crypto ecosystem. Billions of USD worth of Cryptocurrency has been lost to this type of carelessness or what I should consider to be ignorance. As the last count, I heard that over 140 billion USD has been lost to passphrase forgetfulness. The major causes are ignorance and limited knowledge about passphrase and security management. Many people just want to get into the crypto business without the basic knowledge and preparedness required, and I can see how that relates to the new car owner's scenario.
Some hackers claims to be helping owners regain access to their digital funds but I'm taking that with a pinch of salt. If it's really possible like that, then no wallet is safe.
This isn't a huge problem, because first - there's enough units of Bitcoin to satisfy the needs for accounting value, and second - this happens at a much lower rate, because now people are aware of how valuable is Bitcoin, and how it can become more valuable, unlike how it was in the past, when it was just some novelty toy.
They fact that you can lose your coins forever with no chance of restoring them is a fundamental flaw of Bitcoin, when compared with banks, and there's nothing you can do about it. Just like banks have a fundamental flaws that you need to trust them. People should decide for themselves which flaw is more dangerous.