Lets just say
 

If you were only able to get one performance mod for a stock RX8 this year (not F.I.) would would be the most satisfying?
Mid Pipe
Exhaust
Tune Etc.
Cheers
Cooper
(2006 6 Speed)

Midpipe will give you a little power and exhaust will give you some good noise. Do those two

Midpipe

Tune, then midpipe as far as power satisfaction. Exhaust in terms of audible satisfaction.

I am in possession of a stock RX-8 until my buddy (Hoss-05) comes back from Afghanistan and I must say driving a stock sounding car is lame.

Have you changed coils, wires or plugs?
Maybe BHR ignition?

AFE short shifter is a great mod

+1 to what DarkBrew said about the coils. Or the Tune.

+1 to what 09Factor said about what DarkBrew said about the coils. After I put the BHR ones on, I definitely felt a difference. I'm not big on the numbers, but if I can feel a difference, then I'm happy.

From what I've been told a custom tune, BHR ignition coils, and a mid-pipe are the only real mods when it comes to power. AFE short shifter is supposed to be a really good mod too. I'm sending my stock data to MM next week and my BHR coils should be here early next month. Still on the fence about a mid-pipe because I live in VA and the cops will pull you for going 6 over the speed limit here, let alone running a cat-less car.

I would invest in the ignition first. Either the BHR system or Okada Coils

mind you- track time/ driving course is always the first choice;)

BHR ignition and MM tune, all other mods is just noise maker.