I need help. I have had my 2000 Catera Sport for 3 months. I love the car. Just recently, I have been having a problem. After the car has run for at least 20-25 minutes, if I shut it down for 10-15 minutes, I can't get the car to restart. It turns over but won't restart until the car is completely cooled down. Battery and alternator is fine. Any help with this would be greatly appreciated.