AFTER ABOUT 2 INCHES OF WET SNOW MY WIFE WAS DRIVING UP A SLOPED STREET. SHE CAME TO AN AREA WHERE SHE COULD SEE 2 CARS WAITING AFTER A COLLISION. SHE STOPPED. ANOTHER CAR STOPPER BEHIND HER. A POLICE CAR PASSED THE CAR PARKED BEHIND MY WIFE. THE POLICE CAR BUMPED THE CAR PARKED BEHIND MY WIFE AND PARKED. MY WIFE TRIED TO TURN AROUND. AS SHE DID HER CAR LOST TRACTION AND SLID INTO THE PARKED POLICE CAR. THERE WAS NO VISUAL DAMAGE TO MY WIFE'S CAR. I DO NOT BELIEVE THERE WAS ANY DAMAGE TO THE POLICE CAR. A REPORT STILL HAD TO BE FILED EVIDENTLY BECAUSE IT WAS A POLICE CAR. LATER I CHECKED THE RATING ON THE TIRES. PER THE RATINGS GIVEN IN TIRE RACK THESE TIRES HAVE BEEN DETERMINED TO BE UNSUITABLE FOR USE ON ICE.