Before doing this. There is something you should know. Vehicle glass is protected in multiple layers. This helps it to not shatter as easily upon contact and helps protect against harmful UV rays from the sun. 

Please ensure that this method of cleaning protection does not damage, or remove the outer layer first. Otherwise this could be a costly mistake. Maybe visit a junkyard that has your vehicle make and model. Test it on the glass. Come back in a week or two, make sure it still looks good after being exposed to the elements. 

If this actually works and doesn't damage the vehicle glass. Very cool!