what theme should i use for my 15th birthday party bus?!

since you can't do like decorations on party buses everyone just dresses to a theme. a bunch of people do GI joes and army hoes, and i want something different. my one friend is gonna do a cowboys and daisy dukes . i can't decide what to do.. my mom suggested a hawaiian theme but i dont really wanna dress hawaiian. its in january, so a winter / christmas theme wouldn't be as cool. any ideas?