One thing that I think about now and again... think of the ammount of grime and dirt that your seat cushion has on it. These are rarely washed, if ever! Some people end up standing on the seat as they try and 'climb' into their seat and think of all that sweat that the seats have 'soaked' up on those hot days!
My last company dished out hot towels to the passengers and if we ever got one then it was alarming to see how quickly it turned a nice shade of grey as I tried to do a bit of in-house cleaning!