Apparently the '04 is "XM Ready" by virtue of a $400+ option from your dealer. Personally I say take it stock and go spend that $400 on an upgraded head unit w/ XM reciever, and either a pair of SPods or Rear Speakers mounted in the panels behind the seat.

The 04's available speakers for the headrest are (if Im not mistaken) about a $250 upgrade and from all reports WAAYY not worth it. If you haven't figured it out by now the S's stereo comes only using the front channels, you can very easily add speakers behind you that will more than fill the cabin w/ sound.

For the Wing (if you MUST have that gaudy thing) check out Hardtopguy he works for a dealership called Ganley Honda and is usually the cheapest source for stock Honda items.

Good luck with your new toy

Travis