How can you be so sure that at least some of those seats don’t smell like beer and PDA?

When I was very young, my mom taught at a medical school connected with a very busy hospital. She had faculty parking, but patients and visitors would often valet. The parking garage had perhaps 8 levels of parking, and I remember the garage was equipped with vertical conveyor belts for the parking attendants. Every 20 feet or so had a little platform, and a loop. When the platform approached, the attendant would jump onto the platform and put an arm through the loop, and jump off at the desired floor. The conveyor ran continuously and didn’t have any sort of protective gear to keep people off it. Probably if my mom had not prevented it, I would have climbed on and enjoyed the ride until I splattered on the ground. Some other kid’s parents must have gotten a nice insurance settlement around the time these were removed.
Anyway, here is video of the other system in action.