When i bought my 02' 4.6 it had a BRAND NEW pair of rears on it (they still had the titties on them). First thing we did was take it on a 3k mile road trip, and when we got back they looked just like yours. I was so ticked off, ordered a new set of rears from tirerack and had them drop shipped to my favorite tire shop. They checked the alignment and it was "within bmw tolerance" which was something like -2.7 on each side. I had them take every ounce of negative camber out of the rear to get it as close to 0.00 as possible. They got me to -.5 and -.7 and thats mechanically the limit of the rearend on my X5. That set of rears ran me almost 50k before the whole thing needed new rubber again.

btw, i run max pressure in my tires. And I kind of cheated a little at the end of that last sets life span. I over inflated by about 10lbs to make the tire dome and get it off the shoulder of the tire. Good bad.. whatever.. it got me about 5k more miles before i just didn't feel comfortable driving on worn rubber any more.