X6 E71 wheels onto X5 E53

[sharpie]

I think I have an answer to what wheels will fit X5s and X6's.
The FRONT centre bore on the X6 is 74.1 mm the REAR is 72.6 mm.
Genuine wheels from the X6 will only fit the E53 X5 as they have 72.6 mm front and rear (a spigot ring will be needed at the front if fitting X6 wheels to E53)
E70 X5's have rear centre hub as 74.1 mm therefore you cannot fot X6 genuine wheels to an X5 E70 as the centre hub at the rear is 74.1 and wheel is 72.6.
You cannot fit E53 onto E70 or E71 as the front hubs on E70 E71 are 74.1 mm and rear hubs on E70 are also 74.1 mm (X6 rears are 72.6.)
I have just fitted some genuine X6 19 inch wheels (style 258) to my E53 and I only needed a spigot ring for the fronts.