Had my car in at the dealer this week for an engine & trans firmware update. They commented that the 19" rims shouldn't be on this year car as the owner's manual specifies 18 or 20 inch rims only. They are on the money but the factory build sheet has the 19" rims that I have as buyer spec. I like the rims and have no desire to change them to 18/20 but have one question. The XK8 has 19" available but not the XKR, can any of you see any reason why this would be?