Yes, I did.
I'm also renting a room and I clean it pretty often.

Well, I would say you were an exception in the case of a rental car. It is my experience that most people would simply return it dirty. Not trashed, of course, but why wash the dust off if you have no personal stake?
As far as renting a room, I don't think that same logic applies. You most likely keep it clean for your own sake, and only up to your own standards.

But also keep in mind, this is a simple generalization and as doesn't try to fit exactly. But because of the statistical size of any political system that it might apply to, I think a fair one. Ask yourself, in regards to your own reaction, how many people do you know that could also make the same claim? And remember, the honor system only works when we are all honorable. History proves this to be false.