After I turn my car off, the cooling fan stays on for about five minutes. Any idea what's going on? I plan to take it to the dealer to see what's up. Please help.

 

Yes. Possible common causes: low on coolant or bad thermostat, both of which are bad. The coolant issue, if you have gone through a Houston summer without checking it, is easily resolved, assuming no leak in the system. Otherwise, thermostat or other causes of excess heat should be covered by warranty. Hope it works out.