pogofish
Testicle Hairstyle
Letter of the law certainly but grace by any other name & that is how most people took it. Including the police, unless they were specifically targeting car tax that week. Also, when renewed, it was invariably from the expiry of the old disc, I was never one of those who tried to blag a month in between by filling-out a new form or later a SORN Declaration, although plenty did, indeed my local PO would often suggest it! 
I know about the admin, my gran was a sub-postmistress, she had so many days to submit her returns to the area PO then they had a few more days to get it to Swansea. People who renewed at the last minute on the last day of the month were not her favourities as she liked to have all the paperwork away ASAP!

I know about the admin, my gran was a sub-postmistress, she had so many days to submit her returns to the area PO then they had a few more days to get it to Swansea. People who renewed at the last minute on the last day of the month were not her favourities as she liked to have all the paperwork away ASAP!
from what I could understand, it seemed that the mobile crusher was more for the spectacle, as a kind of warning to those who might not tax their cars... not for scooping cars off the street & instantly turning them into cubes!