BMW 5 Series: Remove attached parts 
following use - Saving fuel - Driving tips - BMW 5 Series Owners ManualsBMW 5 Series: Remove attached parts following use

Remove auxiliary mirrors, roof or rear luggage racks which are no longer required following use.

Attached parts on the vehicle impair the aerodynamics and increase the fuel consumption.

    Remove unnecessary cargo
    Additional weight increases fuel consumption. ...

    Close the windows and glass sunroof
    Driving with the glass sunroof and windows open results in increased air resistance and raises fuel consumption. ...

    See also:

    Hands-Free Calling
    1. Push . System responds: “OnStar ready.”. 2. Say “Dial.” System responds: “Please say the name or number to call.”. 3. Say the entire number without pausing, including a “1” ...

    Three-point type seat belt with retractor
    WARNING ● Every person who drives or rides in this vehicle should use a seat belt at all times. ● Do not ride in a moving vehicle when the seatback is reclined. This can be dangerous ...

    Towing
    WARNING Never tow AWD vehicles (including AT, MT and CVT) with the front wheels raised off the ground while the rear wheels are on the ground, or with the rear wheels raised off the ground while ...