It never actually stalls, or hints at stalling... just a random misfire, that gets worse the hotter the engine gets.
It shakes the car.
I have listened to both of the fuel pumps at idle when it does this and there is no change in pitch that I would expect based on a faulty pump relay issue... but maybe I am wrong.
I agree based on logic that if the crank position sensor was missing signals that could be the culprit, but its odd that it seems directly linked to underhood temp. I suspect a componant in the engine bay, but I might be wrong!
If you drive the car at speed on the freeway and then stop its fine, or only does it a bit... only in slow conditions/ and with the A/C on does it get worse.
When its at its worse, its like a couple/3 of plugs leads are off... but its not consistant like that sounds. Its sounds really random, when its cold it runs perfect.

Update
 

Well, we replaced the coil with a used one just to try to narrow down the search... made no difference.
I tried to replicate the misfire by pulling the plug leads off to see if the misfire stayed the same .... It was really noticable when each HT plug was removed...
I plan to do a compression a test next and to check the resistance in the plug leads when hot...

See post #5:

http://www.peachparts.com/shopforum/tech-help/162549-300e-apparent-misfiring-hesitation.html?highlight=arcing

Just one more thing to check...

Update!
 

We found out that the engine needs valve oil seals.
See this thread:
http://www.peachparts.com/shopforum/tech-help/168126-spark-plug-horror-look.html