I just removed my driver side wheel tub in the back. I then cut the opening from stock size to the frame. So the tub is now about 8" wider I guess when you look at it from inside. Can't go farther forward or back thanks to gas filler and floor front. I will go as big as I can. Yet another project here that is making me think maybe its time to buy a daily driver and just put the K5 for toying.