Man, damn nice car! It all depends. What kind of CAI and Exhaust? What brand names are you using in the system? If you cuold PM me or supply those answers I could tell you which one I would do. But like I said, I'm really liking the car.
If your car's like mine and you can't hear your music because of wind or engine noise at speeds of over 90 Kph, then go with the stereo. But I love the sound of my ancient and maxed out 4 banger, so I'd go with the CAI and exhaust.