Intake system

I just bought an 2003 eclipse gs, 4cy, automatic. I've already upgraded the sound sytem and I was thinking about buying an intake or cold air intake system. Ive heard they dont do much for the engine but I was wondering if they did. Plus, I want to buy an exaust. Is there any recommendations for both of these parts that anywould would suggest that would be worth buying??

Injen R/D CAI (cold air intake). Exhaust wise, car back only i would get a Magnaflow street series system. Header wise, Kamikaze header or RippMods header.

http://www.magnaflow.com/02product/cat-backs/mitsubishi.htm

http://www.neweclipse.org/24exhaust.htm

You do realize that if your car is under warranty and by putting on that stuff you will be voiding your warranty. also I wouldn't bother getting a bigger magnaflow muffler unless you want to change the whole exhuast system, the muffler alone will increase the sound volume but no pipe diameter increase woudln't really increase the exhuast flow or decrease backpressure. After a while the sound will really get really annoying especially if you're not having any obvious power increase only sound increase.

I was referring to a cat back system, not just the muffler.

The warranty is only voided is the dealer can prove that the aftermarket part has caused the premature failure of whatever the part in question may be.
For example, if i put the Injen CAI on and my pistons melt, I highly doubt that I would be liable. But if I were to put i nitrous kit on the car, I would be.