In order to run correctly, your BMW needs a good amount of cool dense air coming into the combustion chambers. The BMW cold air intake is responsible for taking in the air as the vehicle is moving, filtering it, and transporting it efficiently towards the engine. Every few months, it will be necessary to check the air filter within the unit. When the filter is clogged, the BMW cold air intake cannot provide the proper amount of air to the engine, and the performance and gas mileage of the vehicle will suffer. Fortunately, the air filter is inexpensive, and can be found in our online catalog for a great price. To install it, simply open the BMW cold air intake, remove the old unit and replace it with the new unit. If your engine can get more air into it, it can make more power. We also carry upgraded versions of the BMW cold air intake for many vehicles, which optimize the bends in the pipes that lead to the engine for the least resistance to flow. It is very easy to install the upgraded BMW cold air intake, and requires only simple tools and a few minutes of time. Included with the kit is a reusable filter, which will save a large amount of money, because it can simply be cleaned and replaced when it becomes dirty. Our BMW cold air intake is made to meet the highest industry standards and has a full warranty directly from the manufacturer. To order your filter or a new BMW cold air intake, visit our secure web site, or make a call to our sales department, toll-free.