This guerrilla stunt that Grant McCann Erickson in Colombo did to promote the SriLankan Airlines Golf Classic had many people momentarily upset and speed dialing their insurance companies... Until a cute representative revealed that it was all a sticker and hearty laughs were had by all. It reminds me a little bit of Vegemite's cricket balls in car windows... But I suppose it could be worse, there could be various giant balls crushing your car.

(I'm docking points for the pun "smashing success", even I wouldn't pun that low...)