I don’t think you’ve made a compelling argument.
Cars are often forged – either fake plates or altered VINs.
In the UK, large sums of money can be bank transfered almost instantly. Certainly much quicker and cheaper than a blockchain transaction.
What happens if I’m scammed? I can go to judge and a transaction can be reversed. How does that work on a immutable ledger?
If the car I’ve bought is a dud, I can ask for my money back. If the seller refuses, I can ask my bank or credit card to reverse the transaction. Again, can’t do that on a DLT, can I?
It sounds like what you really need is cheaper legal services and faster banks. Not a blockchain.
I’m happy to say that land registry should be public – but seeing as it relies on a centralised authority (to uplhold land rights) I again fail to see how a blockchain helps.