The only official stickers are sold via rs.com - at ebay lots of people sell their own made tongue stickers and stuff, but I have never seen a big car sticker. But you´re right: The car needs to be a stones car when driving to concerts!
I bet that somebody on Shidoobee can make them. Those guys are very good at that. I think I have one if you want it. It's not big, but it's the size of a cup's "rounding". There's a big part of the tongue there (Think like on Forty Licks), and then it says "Stones" on the inner rim of the circle. If you want one you can write me. I only have one or two left to give away I think.
i have the tounge sticker on my car..i get it from a record store in barnstaple noth devon...also the other day i saw a stones air feshener inside a car..yeh like to get one of those.
Just take which ever Stones tongue you want to your local sign writer...I've had the original classic tongue painted on the body work of a couple of my cars. Plus now days most sign writers are computerized so you give them the design you want they scan it and you can have a stick on tongue within minutes.