I installed one on a 1997 Chevy Blazer. It seemed to work well. Mileage increased, acceleratiuon increased, and the Blazer was so noisy to begin with it didn't seem to be any louder. Word of caution. Extreme wet weather can get your filter wet as will water crossings off road. On the street you should have no problem. On my 2004 Sport V6 I think I'll leave the stock airbox and just put a K&N element in there. It's better protected and also gives a performance/mileage gain.
After I looked at your message I ran into this thread on the Volant Cold Air Intake. This looks like a real nice kit and it has an enclosed airbox. I hope they will make it for the 2004 V6
I had one for my 2000 Heep Grand Cherokee, it improved gas, acceleration greatly increased, and made this cool aggressive roar when you hard accelerate.