Here's how the movie would have gone with a bigger budget provided by MTV Films;
Intro - A perfect little girl gets second place in a local pageant show when she's a state away to visit her cousins.
Backstory - The mother works at the local megalomart, the father has a harebrained idea about selling a self improvement idea, the 9 steps. The older sister is a counter culture wack job.
The grandmother is a former beauty queen who's only passion is now teaching the little girl what it takes to become little miss sunshine, they live in Arizona, next year.
The Story - turns out the girl who won the local pageant was disqualified so our perfect little girl is now able to compete in this year's little miss sunshine pageant! Golly Gee! But it's in 37 hours, cue clock on the lower right hand corner. Proceed to have the entire family need to ALL drive the hours long trip to the pageant, oh did i mention they're not well to do. Insert hijinks here about cars breaking down, losing bags, grandma dying, taking a side trip to try to sell the motivational program one more time (this time it works!).
Final scene cuts to perfect little girl performing the act that grandma taught her, and getting a perfect score just enough to push her to the title of little miss sunshine.
OK now substitute all the funny things working out parts for things not, substitute a drug using grandpa for perfect grandma, insert a gay suicidal uncle who plays off the now counter culture brother and have the ending still be touching and you have the movie we went and saw, and it was good. Rent it.