The guys here at I to I have a bit of a different approach to handling LPI at airports. They grab the license number on entry and then again a specific places throughout the parking facility. (When you change floors, enter an aisle, etc). they then note the last time they see your car, and connect that location to your entry ticket.
When you go to leave, you can insert your ticket on the POF machine and it will print the location of your car (at least to the nearest aisle or zone) on the ticket. Pretty sharp, I think…Solves the problem without that walk (or drive) around each night..,