anyway SMILE again!

After commiting a daring bank robbery, the Polish bandits tore from the bank parking lot and sped onto the turnpike.
"Karel," said the driver, "look back and see if the cops are following us."
"How will I know?" the other asked.
"He'll have his flashers on, dammit!"
Karel looked back. After peering through the window for several moments, he answered,
"Yes...no...yes...no...yes..."