Where can I find re-usable Vinyl letters and numbers for Windows

[911sc]

I was wondering if anyone could recommend where I can find re-usable Letters and Numbers that you can put on Car windows for example FOR SALE WITH PHONE NUMBER etc..

I checked the usual places like walmart, dollar stores and haven't found anything. So any suggestions will help.

[TYMSMNY]

vinyl is a one time thing. What you're looking for are window clings. Any vinyl/decal/sign company is able to print these for you.