Don't get me wrong - your X5 looks great.

As others have stated, side view cameras are mounted in the bumpers and allow you to see outwards from the front of the car. Perhaps helpful if coming out between cars or a building.

Top view cameras are mounted in the mirrors. They allow you to have a view immediately around the car. Sometimes helpful if maneuvering in tight spaces.

There are issues about side view availability so having it on your X would be a surprise.

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2012 F10 550xi Carbon black/oyster
2011 E92 M3 SSII/black
2012 W166 ML63 Steel grey/porcelain
2007 E93 monaco blue/beige (retired)
2010 E70 35d Space grey/saddle brown (retired)