Third Row and Residuals

[Fredo]

What do people think the effect of the third row of seats will be on residuals? It will obviously be easier to sell the car with them specified, my dealer thinks two years down the line it could be a must have on an X5 like Satnav is now. He was citing previous expereince with the E class Mercedes a few years ago where cars without the third row of seats were worth MUCH less.

For us they will be somthing that is useful rather than essential to have. Not intending to have four kids! Hopefully just two.