I feel like such a trend setter! Went to Bowling Green last weekend and going to Holiday World in two weeks.
Quick suggestion- I don't find that Holiday World is a 4 day park- have you thought about taking a day to explore the resorts at French Lick? It is approximately 45 minutes away from Holiday World, but the hotels (especially the West Baden) ARE AMAZING!!!!!!!!!!!!!!!!!!!!!!!!!!!! I can't tell you how beautifully restored these gems are! Go on line and look (the photos can not do justice to the scale of the interior dome of the West Baden Hotel). Their spa is a little pricey, but nice and there are historical tours of the grounds. As an added bonus, there is a great summer read out called "So Cold the Rive" by Michael Koryta. The book is of a supernatural/thriller sort (think Stephen King) and it features French Lick prominently. I would read the book and take a day trip to the hotels.
Have a great vacation!
-Kelly