Both actually. The 57 got the deepened tubs from Real Deal Steel and the trunk pan comes pre configured for that. I did all of the cutting on the front floor while it was out of the car. Somewhere, I documented the cut lines, maybe on my picturetrail account. Once fitment was completed, I joined (welded) the two out of car. I had sheet metal screwed them before hand so I knew it all was correct On the 55 vert, I used a toe to bumper. no tubs. Two others, toe to bumper. All real deal steel.