my tita bought one early last year, now she sold it. let's just say it isn't the most reliable car out there.
there's two kinds of ///M X5, one with the ///M package basically a regular lightly modded X5 and the other one is the X5M which is the one you saw on top gear. that thing will out run and out handle evo's and sti's, and also out handle the c63 amg.

a total sleeper most people would think it's just a regular SUV.
