James, you are not paying twice. Your otr charge includes registering the car as new with dvla. You would automatically be asigned AB13 CDE or somthing similar as a matter of course. What you are having to pay for on top of the standard charge is the transfer fee of your number plate from your old car to the new one. You'd have to pay it if you were transfering it onto a used car, putting it on the new one is no different.