pcv reroute, do it. The design is retarded from the factory. You'll know what we mean when you pull it off and see inside your shiny new mp already lol.
and traction bars prevent axle warp, by attaching the outer edges of the rear axle to the from in the form of bars. (if you've ever noticed your rear end hop, especially with a lifted rig when you get on it, it eliminates most/all of this)