Thanks for the times. Assuming you dont claim any baggage (or have to check any), you should be in a rental car by 1100 am (go out the baggage claim area, pick up many (see below) free Maui maps and brochures in the kiosks) and walk 80 ft to the right for the car rent desks). You should check-in your rental car by 200 pm, thus you have 3 hours. So much to see, so little time.
The Iao Needle Park is about 15-20 min away, usually cool and nice but will be busy on a Sunday. Never fear, it wont be overcrowded. The Maui Aquarium is on the road to Lahaina (ugh!) about 30 min from the airport. It is new, has standard fish stuff, is overpriced and unvisited by MisterNice. A couple of restaurants are on site.
You can also travel the mostly shore Hana Road to Paia etc and wonder around. A good fish sammish etc place is on the right hand side by the only Paia traffic light. Or go upland a little and wonder around Makawao. A good really cheap Mex restaurant (really good) is Poli's by the only stop sign. Time your way to these places so you can have sufficient time to get back by 200 pm.
My choice on a sunny day would be Iao Needle (it often rains there....ask at the car rent place). Get directions to the Kahalui Safeway Supermarket (itsa on the way to Iao), pick up a few pre-made sandwiches, sushi, subs, some beer or soft drinks etc and have a picnic on a table in the Iao Needle Park (use the brochures as place mats) to save time and money. On a rare rainy day in Maui do the Makawao mini-mex and mini-town tour. Have fun!
MisterNice