I priced the seal out a couple days ago since mine started leaking. Best price I found for the seal itself was from Puyallup Nissan. $52.13 part # 38189-8S110 There are links to a how-to that is posted up on TitanTalk. When I find the link I'll edit and add it.
'05 Mada LE Slate
Mods Done: UpRev, Bilstein 5100s in front, PRG 2" rear spaces, R1 Premium Drilled & Slotted Rotors, PosiQuite pads, Volant GenII CAI, 8K HID Lows, LEDs by ArmaDen, 3k HID Fogs, and Delete middle row console.
Mods in progress: JBA LT, PRT 300-cell hi-flo cat'd b-pipes, Borla xlr-1 muffler w/custom tubing, LED Engine Bay LEDs, Custom Suspension Lift by PRG, Custom PRG front & rear shocks, Custom PRG Rear springs.
Mods in contemplation: GoodHood or custom hood, Steel front and rear bumpers, upgraded front springs, Custom roof rack and cargo basket, Additional lighting.