Well, today I mounted up the big 14.1 inch rotor / big brake kit from the 4.8iS onto my puny 18" summer wheel, WOW! there is about 1/8" clearance all around, and best of all, no spacer required!
Special thank-you to Deansbimmer in Texas, for shipping them to me! they are absolutely HUGE and amazing!!!

I think I am going to go with a BMW Royal Blue either paint or powder coating. I wasn't sure if my 18" wheels would work, but they do! (big sigh of relief!)
thanx again to deansbimmer, you sir, are awesome!
__________________
2003 X5 3.0i (02/2003) sport package, Sapphire black metallic / Black Dakota Sport seats. compass mirror retrofit, trailer hitch retrofit, Prodigy P2 trailer brake controller installed, PDC retrofit, Lumbar support retrofit. heated rear seats retrofitted. Running boards retrofitted and subwoofer install in progress. 4.8is Brakes installed front and back. Bluetooth TCU installed, Rear Fog lights installed. Retrofitted reclining rear seat backs.