you may be fine then dude
same thing happened to me though before i bought a car last year, private plate came off of the one i wanted and was to go onto their new one, my hpi came back as clear but with previous finance outstanding. That plate went onto retention and the old plate went back on. I bought the vehicle from 300 miles away so the hpi and service checks etc were all done over the internet and phone, all clear and good.
The seller though was very good and told me their was still finance on the vehicle even though the hpi suggested otherswise (£8000+) and so i arranged a deal to clear the finance to buy the car. Drove all the way up to collect it and then he called the finance company and then passed the phone to me and i cleared it there and then with proof to be sent to me via post. Remainder was paid to the seller and i drove of. Week later the letter of clearance arrived and the seller also emailed me proof of the account closed.
You may well be fine mate
just saying its very similar to what happened to me and thought the info might be useful.
If it were me, the fact that there might be something outstanding on a plate that was at one stage linked to the car you want would be enough for me to want to confirm or deny with the finance company before i committed to a purchase
