each airaid intake for the mustang comes in 3 configuration with different air filters. You just have to order the part number you want. They have the red oiled filter option, a red non-oiled filter, and a blue filter (can't remember if it is oiled or not). The oiled is the cheapest, and it is what I ordered for my car.
This is what I got on my car: Airaid 450-304 Intake System - Performance Parts
This is the same intake with a non-oiled red filter: Airaid 451-304 Intake System - Performance Parts
Same one with non-oiled blue filter: Airaid 453-304 Intake System - Performance Parts
If you look at the part numbers from Airaid a 450- part number is an oiled red filter, a 451 is a non-oiled red, and a 453 is a non-oiled blue
The above links are for the "Race" versions of the intakes (requires a tune), you can get the same ones that have an insert that does not require a tune. I think the numbers on those are 450-172, 451-172, 453-172.
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