I recently bought a pair of 10x18 merc wheels with some 265/40/18's ( i know they are slightly over sized) and this is the result (sliding door just catches but will pass with a little nudge)
not running any spacers (but ET is about 20/25) will sort out some side pics as i am running 7.5x17 with 215/45/17 fronts and the 10x18 with 265/40/18 rear, I am on the look out for some 245/40/18 to help clear the door and bring the rolling radius down a touch