I exported a car to Eire when my son took it over there. Some 12 months later an organization in Glasgow wrote to me and said I'd been fined £40 for not taxing or sorning it. I wrote a letter explaining that I'd followed the correct procedure for exporting it by filling in the tear off slip and posting it. I also still had a copy of the ferry ticket with the registration number and date it was taken over.
They eventually wrote back and said on this occasion they wouldn't be taking the matter any further. But the tone of the letter was such that I'd had my hand slapped for somehow being a naughty boy.
The worrying thing about all this persecution for doing nothing is that if you're away for a long trip you've got no idea what's building up for your return as Henry seems to have found out the hard way.

You should get a full rebate on the 12 month version, for every un-used month that is "cashed in" before the end of a month.
Yes, for a 6 month version you have paid over the odds, and an amount of cash would be lost - don't know how much off hand because I don't do 6 months for that reason.
Anyway, it's not going to happen is it?!