5.0resto. I bought the non-mass back and it fit like a glove.
The mold is perfect and there are marks on the backing to show where you need to make cuts for seat bolts, seat belts, center console, ect. The only thing is the way it is folded up in the box for shipping. But if you take it out of the box and set it out in the sun while you strip out your interior and remove your carpet, the new one will be flexable and any folds will be gone. Just cut out the holes you need and slap it in.