Viewing it on Saturday - asked him why he didn't put the V5, he basically did the number plate changes online today I think and forgot that the V5 hardcopy isn't immediately online or something. Either way, he seemed genuine enough. Basically, assuming all goes well, he will produce an "invoice" with his passport and driving license probably with mine too in the a picture as evidence that the transaction did happen. Also, I guess the finance company will have my card details too so that will be extra reassurance. Plus this will be done at the dealership as you suggested which might be even more evidence