I can see this causing a few problems

[midden]

The reasons seem clear to me, or am I just a knob  :rollin  Selling vehichle without roadtax forces the buyer to get some and as such they'll require insurance and by getting road tax they won't be able to not register the vehicle under their name or address.  The government should make it that the seller gets a full refund of remaining tax and the the percentage of that is in place at moment, but I doubt they will