I have a 2002 Mazda Miata with 22,965 miles, which recently began having trouble starting while the engine was hot. That went on for about two weeks (couldn't figure what was happening) and then last week it died while I was in 3rd gear (manual transmission). Had it towed to a mechanic who said it 'drives like a dream!' And couldn't find anything wrong with it (I picked it up, drove it 6 miles and it died again). I had it towed to the dealership where they ran a diagnostic and said the cam sensor is shorting out.
Does that sound like something that would cause the car to not start unless the engine is cold/cool and to die while in-gear (not idling, idle's fine all day long -- just running, in gear is when it dies.)
Yes it does. If the dealship found a bad cam sensor, then have it replaced. Usually with intermittent problems, the sensors can be the problem, but they dont always show bad. You might be very lucky. I hear people who try tons of things before they find a sensor bad.