I once wanted to buy a European car that through REVS, came up with the statement, "...INTEREST ON THIS CAR".
When I confronted the owner, he stated that there was still a residual lease and that I could pay 1 cheque to him and 1 to the institution.
Not being totally convinced, I got permission to talk to some representative at the institution and together we came up with the idea that myself and the owner complete the transaction at the institution.
Once we arrived at the institution, all papers were signed; but before handover of the 2 cheques, the institution did a further check to see if the then owner had taken out another loan on the car, which came out negative.
The institution then told me that REVS would still state "...INTEREST ON THIS CAR" for another 48 hours - but the car was clear of any encumberances.
You just need to make sure that there's not more than 1 loan on that car before you pay off the existing loan ie. 1 cheque to the owner and 1 to the institution > paid at the institution.