Our mechanic changes our internal air filter every time we have the oil filter changed. We bought a used car and they obviously had pets and messy kids. The car looked clean when we bought it, but the stains in the seats (and ceiling) started to reappear after a time, and the car was always dusty. So I also changed out the protective floor carpets which were deteriorating and that along with the air filter changes has really helped. The stains, I just work one at a time. Have I said lately how much I hate this car.
I wonder too if I wouldn't be better off taking a nap at around 4 (my witching hour) and then staying up later. Except I wouldn't do anything after dinner anyway, I don't think. I do tend to not eat late at night-usually dinner is the end of it- so it might help with my food issues.