ADVANTAGE RENTAL CAR.

I rented a car for a week and when I returned it I forgot my GPS inside it. I know I forgot it in the car because I used it to drive to the drop off destination, Denver airport in Colorado.
I called the day after (Saturday morning) and they asked me to call again on Monday because there were nobody in the Lost & Found department. Long story short, on Tuesday they responded my call telling me that my GPS was not there, and since they were unable to have a record of all the people who interacted with the car (received it, cleaned it, etc), no actions will be pursued to clarify...