Re: 2003 Mustang v6 auto
Just get a K & N FPIK and call it the day,.... But on a side note, I DYNOED before and after of a stock filter -vs- K&N -vs- K&N with CAI.... 4+k&N alone over stock and the CAI with K& N was 5+hp over stock..... In other words, Just buy the filter alone and call it the day. Spend you money on other things like UD pulleys which will give you a solid 8hp.
Also since you have a AUTO, I would also reccomend a tranny cooler, which will help in the LONG RUN for the longevity of your tranny. That will set you about $60 for the tranny cooler. Another thing you can do since you have a new V6 mustang is go to your local Ford Auto Recycling yard and spend about $30 for a used rear sway bar from any 94+GT mustang, that will give you a little more rear end control. 4 bolts and it's installed.