Mazda Repair: Engine wont start when hot, engine temperature, battery terminals

Question
I have a 1999 Miata (Anniversary Edition) with 98,000 miles.  The problem started last summer.  When I drive the car 10 miles or so and temperature is 90+ (I live in Houston so temperatures are consistently in 90's) and turn the engine off for a few minutes, it will not restart.  The motor cranks, but will not fire.  I have found that if I let it cool off for half hour or so, it will start right up; sooner if I open the hood.  I have had the car in the shop a couple of times for this, but the mechanic has been unable to reproduce the effect or diagnose the problem.  The engine temperature is normal so it is not overheating.

Answer
the main areas to look at when you have a hot no start are

the air filter (clogged)
fuel not reaching the injectors
corrored battery terminals mainly to ground ( check the body ground or engine ground)
or a faulty EVAP system

thats a good start and the most main causes for the mazdas