Sounds really good. Kind of reminds me of my Racingbeat header and muffler combo on the first gen. Did you look at the Racing Beat system? I don't know how much it costs but $900+ sounds a bit high, then again, you utilize 2 mufflers and it might be very different for the 8 than the 7.

That better not have been a cold engine you were revving.

No offense but the general Rx-8 community is for lack of a better term "rotary stupid" and they don't know how to properly take care of their rotary engine. I'm not saying you're one of the dumb ones but about 80% of the Rx-8 owners at the last Mazmart meet bounced off of redline leaving the meet right after starting their cars up on a cold engine. Just making sure that you know to warm it in idle for at least a few seconds. If you don't the engine won't last as long and you'll just feed into the negative rotary reliability stereotypes.