I believe, they're called Shark Fins, Honda-Access OEM option accessory. I could be wrong, I don't have a hatch never looked into it.
They go for $150-$250... try looking for replicas if that's too pricey for you. With $200 you can start building a turbo kit :O http://www.weaksauceparts.com/store/product.php?productid=17719&cat=1870&page=1