The rear wheels have a wider track than the front, the rear wheels are wider than the front, therefore the outer edges of the rear wheels are farther from the centre line of the car than the fronts. The track width is measured from the centre of the wheel width.
I am ignoring the tires widths as they could vary.
I have no idea if this the answer as I am only guessing what the question was, as the post title has changed, so I guess it not the answer anyway.