I've been using these for at least 5 years and it has to be hands down the best thing for taking care of my car I've ever used.  I leave it under my seat and it's perfect for when you get out of the car wash and need to dry your car off quick so you don't get water spots.  It's also great for wiping off the inside of the car, or even washing the car at home.  Seriously a great buy.