I just had this discussion with my CA as I am ordering a 50i. My dealer flat out does not recommend the factory installed single monitor option for several reasons...
1. Location
2. When you fold it up to get it out of the way, it covers part of the arm rest making your elbow unhappy.
3. You can't see it from the 3rd row if you have it.

The Dealer installed BMW option with 2 monitors and 2 players was quoted to me at $2700 installed. It installs into the backrest of the seat and extends up to sit behind the active hear rest. 2 monitors, 2 DVD players, 2 wireless headphones.

Pretty pricey. Other much cheaper options are available but the dealer installed option can be written into the lease so you can residualize some of it.

I have an ipad...

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