Your car does not weigh any where close to a decked out race UTV, nor are you pounding whoops for miles on end at 50-70+mph. I can see where the CVs could get heated up real quick in a race environment. They are no a huge CV on the X3. With that said I would of ran the car until the axles said no more.Hmmm, I have 200hp to the wheels, quite a bit more at the crank, yet I ONLY drive in 2wd when in the desert. Weird. Stock axles, 3300 miles on the machine. Something isn't adding up with that story.
Until you have been on a race course it is hard to understand how brutal they get. Especially after the trophy trucks have already gone through. We were on part of the Mint 400 course a few weeks ago. Those whoops are no joke.