Engine off – does not start anymore

Hello, I stayed yesterday with my Saab 9-3 Aero MY03. Vehicle just went off during the ride – no inspection, no error medication, nothing at all. Luckily, I only drove about 20 km/h at the time…not even thinking what could have happened on the highway… I then tried to restart the car, but didn’t go any more. From time to time he once again took one to two seconds and then he went out again. Benin was still a good quarter full. Today it went then ga r no more. Then only with tow truck went to the workshop. Does anyone have an idea??? Many greetings bcn31