just get some 220 grit sandpaper and sand down the powder coat. you just need to do it until it's no longer shiny. i spent a few hours doing mine, but i was being anal getting all the chips out and crap from when they welded the frame.
i've got a pic of it after being sanded at home. i'll post it later this afternoon and you'll see what i mean.
another thing to think about with the tape is that there's a good chance it will leave a bunch of residue if you try to remove it (especially if it's been on awhile).
if you paint it and don't like the way it looks you could always use the tape then.