it will add some mpg, but if thats what you are looking for there are
better ways. the cost of adding it will not be worth the gas savings.
and depending on where you live you could end up hurting your mpg. one
of the cheapest ways I have found to increase mpg is make sure tires
are full, get good spark plugs/wires (i prefer the bosch plat 2or4
prong) and a good air filter. saves me 4-5mpg. at 15000 miles per year
thats about $500 each year, that justifys $100 in parts. while $100
savings from a $250 cold air system takes alot longer to get any real
savings.

I am under the impression that all the newer cars already have cold air
induction.  If you follow the air filter intake, you should find it
opens up around a headlight in the front rather than being open in the
engine compartment.  We have to really watch that on Jeeps because that
damned fresh air scoop will scoop water like crazy when crossing a pond
or creek.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's