If'n you are cheap like me, take a look at the Stealth intake mod. It is just removing the stock airbox from underneath the car and pluggin in a $25 universal 3" air cleaner. Mine was in fact $25 at Autozone last week. Just a little more sound, barely noticeable.
I found that heating the connecting end of the new air cleaner helped as the male end of where it plugs in is 3-1/4" so it is a snug/secure fit. Make it good and warm, not hot. Use a space heater or hair dryer. Also lightly use a hose clamp for added security.
To prevent getting water into the air cleaner, I also cut and installed a coroplast (think election sign material) undertray back just past the control arms. It will take some fiddling to fit well but is good insurance to save the motor from possibly ingesting water splashed from the tires. This is the perfect time to get used election signs for undertray material.
I'm now tempted to crack apart the stock box and see what's really in there and if there is an easy way to install a panel filter inside the box.