the aero kit may be purchased from bmw dealer. kit contains 1) front spoiler, 2) rear apron, 3) fender flares, and 4) running boards. 5) door accents are separate option. part number depends if you have headlight wash system and park distance control. (look in X5 accessory catalog for details)
painting is required. i've heard issues with durability (doesnt stay on) from my dealer, but i've had no trouble. make sure you have a good installer. good luck.
2005 X5 4.8 with Aero kit
2003 M3 with SMG