Look at
this thread on outside storage, particularly Post #17. It appears to re-use the spare tire carrier space.
I am still looking for another thread that definitely re-used the spare rack.
A word of caution about the rear-mount spare. I had one on my popup camper, and it ripped off of the bumper mount on some Forest Service road. I welded another one to the bumper, and it stayed. Point is, it shakes and rattles back there, so it must be a sturdy mount.