The engine stops while driving slow-looking for a car park, have to slow down to stop the moving car before able to put the gear to free to restart each time the engine stops. No abnormal alarm indicated & the air condition also stopped. Peugeot authorized workshop unable to identify the problem. This has happened 5 times so far, I believe it is very dangerous if the engine stops during high speed driving. Please advise..

Update from Nov 9, 2014: Peugeot 407, 3.5 years old: the engine stops while driving at slow speed, the air condition also stopped. Had to slow down the moving to a halt before switching to free gear to restart the engine without any problem each time. This has happen 6 times so far, all during slow driving. First time it happen when the car is two years old. The Peugeot workshop was unable to identify the problem as their computer could not find anything. This can be very dangerous - driving a car when the engine dies on you... Please advise.