Hey - Im also thinking about the X5M front spoiler and I know its been done and Id love to hear your experience if you do it.

As far as I can tell

1) You need the M front spoiler
2) You will need the side arch inserts left and right and you will need to cut them to fit the X5M bumper.

Go park next to an X5M and youll see what I mean by #2 above

3) There are several X5M bumpers (2 I believe) and I for the life of me cant figure out which one is the one that makes sense.

4) You will need to figure out what to do with the fog lights (in this mod you dont need to change headlights) - perhaps a LED strip in the air intake of the new bumper might work?

Keep us posted as there are a few of us whod like to do this.

Alex