Where can you buy the car paint to write on windows?

I have no idea what they are called, but you know the paint stuff people use to write on their car windows for whatever occasion they need it for? Where can I buy them and how can I know they are 100% washable. I'm going on a road trip with some friends and we are using my friends car, she said we could write on her car if we could find the paint and prove to her its 100% washable. Where can I buy them and how do i know they won't leave residue on her car?Where can you buy the car paint to write on windows?
Walmart in the car section has a bunch of different colors and im pretty sure they are 100% washable but it should say on the label! have fun!Where can you buy the car paint to write on windows?
http://www.amazon.com/Duplicolor-Car-Art鈥?/a>





here it is at amazon. you can also get it at walmart and lowes/home depot
You can use white shoe polish. when ready too take off just use flat razor blade to scratch off.
It's called Kiwi shoe polish.
wal-mart





and.they.say.it.on.the.thing..