When a BMC air filter is introduced to the air box of your 2003-2004 BMW X5 4.6is, it will awaken your engine. The correct BMC filter will make your BMW perform better and filter more than the one it left the showroom with. BMC’s patented filtering technology and manufacturing process is second to none. Purchasing the proper BMC rechargeable BMC air filter for your BMW X5 will pay for itself and save you money over time.