I have the same problem on my 3 door, stopped twice this year, leave it about 10 minutes works fine, I have just started checking all sensor plugs and wiring but until it goes again have no way of finding it, I am carrying a few screwdrivers, multimeter and wiring diagram with me as I can only find it when its broke, but fuel relay or connections sounds feasible will attack that with the meter if it happens again. Unless there is any way to check it, I was also thinking of cleaning the terminals on the fuel pump just in case. So I am interested in any comments on this as unreliabilty is a pain.