There are more and more articles being published lately on this topic.  Whether you are a big repossession company, or a one lot dealership most of the requirements are the same. 

You have to remove the property, account for it, and make a list of what is in the vehicle.

You have to keep the property together in a "secured and monitored" location with the list attached. 

You basically must keep the list in the customer file for the rest of the note and beyond.

You have to let the customer know that you have the property available for them to claim, if they choose.  Have a form with all your information and the customer information already entered that they sign and date when they claim their property. 

You have to give the customer a period of time in which they have to pick up the property (this is defined by the state where you operate).

If the customer does not come after their property, you have to dispose of it.  AND, of course, there are rules about how that can be done. 

This seems like a lot, but squabbles about personal property can equal legal entanglements that you really just do not need.  

Everyone should look at their personal property practices and make sure the customer, your operation, and your employees are protected.