I dunno, the conditional title requirements, which would seem to apply here, look to be tedious to say the least.
All it takes is for the titled owner to say "hey I want my vehicle back" and you are out your $5000, or for him to say "I want $5000, too" and you are out $5000, either another $5000 to pay off the owner or the original $5000 you spent to "buy" them to begin with.
Which is why I run from this problem.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.