For 2004 hatchbacks you will need to either swap your bumper skin and foam piece covering the rebar to a 2007+ and add a mazdaspeed rear valence, or just upgrade the rear skin to a mazdaspeed bumper skin (I believe you will need the foam piece either way). You can find them at your stealership.
I'm looking for something like this but for a 2004 with the stock spoiler. I have seen the spoiler lips on ebay but they're too small and they don't cover the whole back of the spoiler.