I'm looking at buying a 2007-09 and came across a listing with these doors. I've never seen panels like that before. Maybe it in an accident and had nonstandard replacements, but I only have access to the free MyCarFax which doesn't show as many details as the full CarFax, and there's no indication of an accident.
They are most likely a dealer add-on or aftermarket door guards. They protect the door from dings when hit by other inconsiderate owner's car doors. Think about parking lot damage when someone swings a door open and it hits your car. Those rubber strips prevent paint damage/dents/scratches, etc.
Rental car companies aren't known for spending money on any accessories at all when the car is in revenue service or turned around for resale. This was somebody looking to do the "bubblewrap" treatment, paranoid of any scratch or blemish. Plastic appliques like that are great for hiding rust, and also create new places for moisture to collect and start even more rust.
To be clear: those don't look like replacement door panels. They are most likely just body color-matched plastic strips which are attached to the door via double-sided tape (the use of tape is standard and common: some high-end body kits use double sided tape to attach some panels).
In the UK, some Toyota dealers actually added strips like these to some of the vehicles they sold. do not know why, but I’ve seen similar strips on a few 2nd Gen Prii in the UK, often colour coded. iPad ? Pro
