What do people use to write on car windows?

White shoe polish.

These

They always used soap when I was a kid.

That comes off with itself and water. ;)

shoe polish is what I know people use.

So in this day and age, they generally get stuff that is specific paint for car windows. You can get it anywhere they sell party or school spirit stuff. Or amazon.com I’m sure. It just takes warm water to come off unless you leave it on forever. Then it takes soap too.

If it ever gets cranky about coming off, the Mr. Clean erasers WORK.

You can use shoe polish but they have stuff specifically for it… I usually find it in the party section at Wal-mart, also try arts and crafts.
Edit: and they are way cheaper than the ones I saw linked earlier.

Liquid Chalk Pens, You can write on glass and such and it’ll rub right off once its dried

probably this sort of thing
that’s what everone i know has always used

crayola has a window marker that works just like a big dry erase marker. they have lots of bright colors and wash off in a car wash.

http://www.crayola.com/products/list.cfm?categories=MARKERS,WINDOW

If the car is dirty enough, you can just use your fingers
Though, you probably won’t get the same colorful effect.

thank you! I got some!

Here in Ft.Myers, Fl it is carried in A.C.Moore The crayola window marker. Thanks so much .