The microfiber cloth works great on the inside windows. It will remove all that film that accumulates on the windows from the vinyl. I've picked up microfiber cloths from just about every place that sells car stuff. Schucks/Kragen/Checker (depending on your locale) has them, GI Joes, Wal-Mart, Target, AutoZone, etc. Be sure to look for the thickest ones. Some are real thin and will wear out soon. Meguires makes a real nice one. They run about $3 to $5 depending on quality, but they last years. I keep on in the car just to wipe the interior glass if it gets foggy. The can be used on any surface also, not just glass.