Worth looking onto this a bit further, sure someone will have a better answer, but have found this from another forum explaining the position briefly
You should always consider carrying out checks before you buy a car. There are agencies, such as HPI, who will search their databases and let you know whether the car has a finance agreement registered against it, or whether it has been declared an insurance write-off, and also whether it has been reported stolen. Incidentally, stolen cars (in common with other stolen goods) will always remain the property of the person from whom they were stolen.
Something interesting to note is that with Hire Purchase agreements (unlike a loan) the car belongs to the finance company right up until the last payment is made.