I am pretty sure that I want to put OEM Style 121 wheels on my '05 X5... these are 6-series wheels with 19 x 9.0 in rear and 19 x 8.5 in front.

I have confirmed that the offsets of these wheels will allow them to fit in the wheel wells without spilling out or causing rubbing, and that they have the same bolt pattern (5 x 120mm) and center bore/hub diameter (72.5).

I am trying now to confirm that Michelin or Birdgeston 255/50/R19 tires will fit on these rims all across the board (I think they will) and that the thread type is the same for the lugs.

Is there anything else I need to confirm? The BMW dealership has recommended that I not try this, but they didn't give a compelling reason not to. Is there something I'm missing? Any good reasons why this is a BAD idea?

Any advice appreciated! Thanks!