Don't run a staggered set in an Xi unless you can make the F/R tire circumference within 1% of each other. Failing that you risk burning out your transfer case clutch pack becasue of the F/R axle speed difference.
See this one:
http://www.e90post.com/forums/showth...42#post3248942
Also see this one, pay attention to posting #20 and 22:
http://www.e90post.com/forums/showth...t=differential