There's always some kind of mess in my car. Spilled coffee, greasy hands, fogged-up or bird-pooped-on windows. I usually fumble around for whatever paper napkins I might have stashed away, but then I saw Quickie microfiber towel 24-packs on Amazon for $10. They turned out to be a way better solution.
They're reusable towels that clean up anything in the car without creating a new mess, as paper napkins or towels do. It's the best 10 bucks I've ever spent on my car.
Paper napkins I've grabbed on the road just flat-out suck because they're tissue thin, and they always fall apart. To make up for how crappy they are I always used a ton of them, but they damage the environment and just amount to more rubbish in the car.
I don't need a high-end microfiber for just cleaning up little messes while on the road, and Quickie is much cheaper. Each towel is 14"x14", and can safely clean even my headlights or sunglasses.
It's a great return for little cost that keeps me, and my car, happy.