I had a Maserati that was doing the same thing as your car, I would be driving down the road and it just cut out as if it had just run out of fuel. I found out what the problem was and it was the fuse box as in lots of cars now in the fuse box it has a printed circuit board and when mine got warm the circuit board would flex and a connection would brake and once it had cooled down the car would start again. I don’t know what type fuse box you have but if it has a printed circuit board in it that is the first place I would look good luck and I hope you sort it out
Martin
January 2007