i dont think that it is the running temp that is the problem, but the spikes inside the heat of the car when it is just sititng parked in the sun. i mean some cars can get up at 150 degrees inside.

though the only major component i'd be worried abotu would be a battery, but since this shouldn'thave a baattery it shouldnt be that bad.

as for operating temps, if it's closed up back there with it's vents blocked of i'd worry