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"but for the sake of good neighbourly relations and not risking a brick through your window, you could warn him first before reporting him.
I'm sure he'll shift it pronto if you tell him the facts."
We've already argued about whether or not it needs taxing. He said no, I said yes, on repeat. God fed up and said I was considering reporting him and he basically said bring it on because he knew he was right.
I won't report the SORN car-on-road element because I haven't brought that up with him, I think the tax issue is the most important.
Not that the DVLA will do anything but it has made me feel a little better!