handy offsett calculator that mate cheers . ive just worked it out and i think they would just go on . im currently running 8.5 rears with et38 so the x5 rims are 9j fronts with et 48 , according to the calculator the inside of the rim is 16mm closer to the strut and the outer edge will sit under the arch by a further 4mm this means i can use atleast a 10mm spacer to get the front how i want it.
the rear works out at 26mm closer to the strut on the inside and the outer edge will sit an extra 12mm further out from my current rims , which looking at my car i think its possible without arch work .
only thing im not sure about is the front wheels scrubbing the arch liners on full lock????