See also:

Styling
With the X6, BMW takes aim at a model that's been relatively unchallenged in the SUV segment: the Infiniti FX. The FX is a true performance SUV — it shares its platform with the Nissan 350Z sports ...

Remove attached partsfollowing 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. ...

Following part replacement
The same breaking in procedures should be observed if any of the components mentioned above have to be renewed in the course of the vehicle's operating life. ...