There are a couple of errors in your reply about transferring a reg from a crashed car. Firstly, you wrote, "You cannot transfer a plate from a write-off". It is possible to transfer a plate off a write-off. The V317 transfer application form states: “If your vehicle has been written off it may still be possible to transfer or retain its vehicle registration number if: your insurers have not scrapped the vehicle and have agreed, in writing, to you transferring or retaining the vehicle registration number (include the written agreement with your application); the vehicle is available for us to inspect (we will also ask for an insurer's engineers report); and you have met the conditions for transferring or retaining the vehicle registration number."

I presume the "engineer's report" is a description of the damage to the vehicle and why it is not economic to repair it. In my case, the insurers sent the report directly to the DVLA Local Office, so I did not see it. I'm not sure why they need the report, but they do insist on having it. When an insurance company writes a vehicle off they are effectively saying it is not economic to repair and we will pay you £xxx and take the "wreck" off you. You can agree to accept that payment once the reg is transferred. This seems no different from agreeing to sell an undamaged car for £xxx once you've got the reg off it.