I don’t think that any car rental agency ever cleans the insides of their windshields, at least not Alamo, Enterprise, Dollar or Hertz, all of who I have rented from in the past.
All they do is give the car a quick vacuum and run it through the car wash, they don’t even use blowers to dry the car so the windshield and the outside rear view mirrors often has spots on it. On driving the car out of the lot I usually use the windshield washers to clean off the spots left from the car wash.
Sometimes I find the inside windshield so dirty, especially when driving at night that at the hotel I grab a hand towel and go out and wipe down the inside of the windshield and also the rear view mirrors.
Mr. Elliott