Originally Posted by G-Man2011
I could be wrong but this is what a BMW tech told me. Any XDrive built before mid 2007 can not have upgrade or staggered wheels. BMW redesigned xdrive system for 2008 which explains why they now offered factory staggere on x cars from that year on. As i was shoppping for wheels for my X drive the guys at Tirerack said same thing to me. He would not put staggered on 2007 and previous drivetrain. Maybe this could be your issue. The production date of your car.
Staggered WIDTH has nothing to do with anything. If the rolling circumference of the front/back tire/wheel is within 1% or so there should be zero problems, esp with the tire sizes and offsets the OP has. The only issue in some cases is clearance with fenders and so forth but not with the sizes being discussed.
I have never heard of a "redesign" of the Xdrive system on e9x vehicles in 2008, plus there are plenty of people here on this forum with 2007 xi cars running all sorts of wheels/tires, some with 20" and lots with 19". And in any case how would this mythical old Xdrive system "know" the car had wheels and tires on it of identical rolling circumference as stock but different front/back widths? Use your brain man.
OP, this is so off the wall I wonder if they maybe damaged your car somehow and are pulling excuses out of their ass to cover themselves.
BTW I went to Tirerack just now and checked, they list staggered 18" as one factory option on 2007 xi.