The 2010+ cars, and especially the BOSS already have cold air intakes from the factory. I think that is why Ford is saying there is almost no performance gain from going aftermarket. However, 2005-2009's have a pretty good and documented improvement by going with an aftermarket intake. Many of the aftermarket intakes have larger then stock MAF diameters, which also allows a larger volume of air to pass through. More air equals more power.
I'm asking which of the airaid kits I linked to above would be the "race" kit from american muscle. I'm assuming it is the 100mm MAF one, but I would hate to order one and find it is the more restrictive "No tune required" intake kit. American muscle does not show the manufacturer part number on their website, so I can't cross reference them myself.
As far as filters go... It is known that you are taking on some risk when installing a performance air filter, but many people have taken that risk without ill effects. A good flowing filter will generally not filter as well. It seems like most mustang CAI kits come with an oiled filter.
2008 Mustang GT Deluxe, Black, Manual Transmission, Black Cloth Interior
Show: Katzkin Leather Interior, Matte Black 10" Stripes, NXT Step Performance Axlebacks, Pypes M80 Mufflers (mid mounted), CDC Sequential Tail Lights, 14" Shorty Antenna, Ford OEM Plenum Cover, Ford Semigloss Black Painted Valve Covers, Leather Wrapped OEM Steering Wheel
Go: Airaid Race CAI, BAMA Tune, J&M Lower Control Arms, JLT Oil Separator
Coming Soon: Motive 4.10 gears