I would have to agree that a lot of people even car dealers did not know of some of this as came up in a conversation whilst I was over last trip https://uk.finance.yahoo.com/news/drivers-not-adequately-warned-over-011241813.html
“Anyone buying a new car will no longer be able to benefit if there are months left on a car’s tax disc as their tax will no longer be transferred with the car, so buyers will need to renew their disc straightaway or risk facing a fine.”Paul Watters, head of roads policy at the AA, said: “Vast numbers of people could be hit, as many car sales involve someone saying ‘I’ve put tax on the car for you’.
“That this will no longer be possible has not been well-communicated at all.” Under the new rules, car sellers must tell the Driver and Vehicle Licensing Agency (DVLA) immediately of the change of ownership, and the new owner must register to pay tax before driving the car away.
It stuck in my head when I was reading it in the UK as most people sell a vehicle with 12months roadtax.
oops forgot that the start date is 1st of October