For performance, the two best axleback exhausts I've seen (dynoed) have been the Greddy Evo2 and the HKS Hi-Power. They are very similar, except that the Greddy Evo2 costs about $150 more. For your Cold air Intake, i would go with AEM. The reason is this: it uses 2.5'' tubing, where the other brands (such as injen, K&N, secret weapon) use 3'' tubing. Now the flow to the engine is not all that much more with the larger tubing, however it is MUCH easier to install the AEM piece. To install the AEM intake, you only have to remove the stock air box and the front drivers side wheel. to install the others, you have to remove the bumper and fender well liner. a big hassle. Also, the AEM CAI is the same CAI as the TRD one you can get from the dealership, just with different badging and a $200 price jump for the TRD name. Buying the TRD parts aftermarket rob you blind. You should see about a 20hp gain from these modds. not bad for costing under $1000. Neither of these modifications will hurt your car.