Are you asking about a BMW with the N63 V8 engine? I'm surprised you haven't received notices from google by the mere fact that you typed 2013 X5 5.0.
Just type BMW N63 engine and see the results. It's infamy & calamity follows the same notoriety as the n62/n62TU engines that proceeded it...except it actually got a recall similar to the old M60 V8 engine.
Buy with caution...make sure your eyes are wide open if buying any BMW with the N62/N62TU/N63 engine...you "may" find one that doesn't have problems...if you do "hold on to it because it is rare".
If you want a V8...you may want to hold out for the
N63TU engine...but that would put you into an F15 X5.