I purchased a BMW X3 last month & noticed a rubbing sound everytime I back out of a parking space...I inspected the pssg front tire today & noticed that the outside tread is chewed up from the rubbing. I took it to the dealer (the clock needed to be replaced also), and they said they "can't find where it is rubbing, but they know it is rubbing somewhere since the tire is chewed up". They said all the parts and bolts are where they are supposed to be and they want me to monitor it to see what happens. Has anyone else had this problem? Any suggestions?

The rubbing sound you hear, does it do it when you turn the tires both ways?

It only does it when I am backing and turning the wheel to the right (towards the passenger side).

You should take it back and take one of the service techs out for a ride and make the tire rub when he is in the vehicle with you. And also tell them that you want a new tire.
If they know that it is rubbing somewhere they should have kept on looking into the problem until they found it.