My 2000 xj8 won't start sometimes. It seems if it is warm out in direct sunlight overnight it occasionallly won't start. But more often if I drive to the store approx 10 minute drive, I come out about an hour later and turn the key and get a gearbox fault on the dash, also I cannot get the shifter to go into neutral with the key on, recently it happened and I pushed the brake put it in neutral and it started. Usually it won't let me put it in neutral.