If aftermarket intakes were so effective in this modern day of EPA regulations and minimum mileage requirements, why aren't the auto manufacturers going to K&N, or Airaid or Volant and saying, "Please design an intake for our automobile, because our engineers are incompetent fools and have no clue how air flow works in relation to engine performance"? The bottom line is, the vehicles designed so that every component and system works together in fluidity and harmony. When you change out one sytem, it affects the others. If you modify one system, you must modify the others in that train to affect a change in performance. If it ain't broke, don't fix it.
"Question: if they are useless why do all modified show jeeps have them. Even the future concept Moab Easter jeeps had them installed. Most of the Jeeps at Sema had CAI's"
Answer: Because SEMA is to show off manufacturer products. Those vehicles rarely if ever see a production floor. It's a showcase event. OEM intakes are ugly. Aftermarket ones are shiny and have smooth lines and convey a sense of performance, when no real performance is necessary in these vehicles because, again, they are for SHOW.