That was one thing I hated when I worked as a porter. Newspapers come in handy when removing all the tar off the inside of a window. Once most of it was off, then I used the paper towels. Still grossed me out when having to sit in the car with all the food and garbage every where.
I smoke in my car and never let it get that bad. There is a point where it becomes unsafe trying to look out the window especially when it's raining at night and you get the glare from headlights coming from oncoming traffic.
People always seem to amaze me, and I'm one that doesn't keep my car spotless all the time.