we own a 2004 crossfire, we picked it up a year ago, with 25000 miles on it. we love driving the car. but we are having a problem with it right now, and we can't drive it.

The car is a standard, and stock, the first time i noticed it was after driving home from work one day, which was about 15 miles, i ran the car about 80 on the way home. i made it home,but went out to go somewhere and the car wouldn't start after it cooled down,it started up and i didn't have a problem, for about a week. then i drove it about 60 miles away and I stopped at a buddies house and let it sit for aout 15 minutes and it started up and drove fine all the way home. i then took it to chrysler and they said they found nothing, so i drove to my house which is about 300 miles from there made it 230 miles went to stop pushed in the clutch and it died, i let it sit about an hour and it started and made it the rest of the way home. so i put it in the shop again different dealer and they found nothing also, but recommended a fuel cleaning, fuel filter,and said the computer needed up grades, so we took it home. put a new fuel filter on it and no difference. Now I can just start the car up and let it sit in my yard and after it warms up it dies. Sorry for the novel, but like i said we really love this car and no one can figuire it out. any ideas would be appreciated.