Although the police can technically get involved with a Title loan, it is rare that they do.
If you get stopped for some other reason and they run your plates, there is a chance they will call it in but to be honest, it's the company that you owe money to... that is your real problem.
Unfortunately, these people are vultures and they prey on people who have financial problems. They are more or less depending on the fact that, the people they loan money to, will be unable to pay it back on time.
Late payments are not accepted by these people and they can and will repossess your vehicle right away.
By law they are supposed to give notice, but they often don't do that. I think a lot will depend on which State you live in and the laws governing it.
Title Loan companies usually have their own people out looking for cars, so I very much doubt the police will bother you.
Think about how many people default on these things. If the police spent their time chasing people who had defaulted on loans, they wouldn't have any time left to catch real criminals.