The Performance Package arrived at my house today. Frankly, I am very impressed with it. The cross brace, which mounts to the square tube frame members in front of the strut housings, is very well made and should be more than capable of handling the forces involved. What isn't apparent from the pictures but is essential to its structural integrity is the fact that the cross brace is not a flat piece of steel but rather a gently curved flat tube. Picture a very thin airplane wing. This means it has 2 curved sides and a hollow center making it highly resistant to bending. And since the frame tubes it is attached to are the ones most likely to deform from suspension forces, this should be a real solution to the problem. Plus, I think it looks great under the hood. My Z8s are silver and the black looks totally at home in the engine compartment. Next comes the strut mounts which are, as I expected, much stronger than the originals. What BMW did was replace the top plate, which is made of aluminum, with a top plate made of steel. Since this top plate is in direct contact with the underside of the tower, any tendency for it to bend or deform was going to transfer into the aluminum structure of the tower, which would show up as doming. Plus, since the 3 mounting studs are press fit into the top plate, any tendency of the plate to bend or deform would cause the studs to splay out, exactly what some owners have seen. With the switch to steel, any tendency of the top plate to deform should have been eliminated and to provide further insurance, BMW has included steel rings which mount on top of the towers and form a steel sandwich to protect them from deformation. I am convinced that the steel top plates would have done the job alone so I continue to believe that the real value of the top rings will be to help flatten out any existing doming when the sandwich is tightened down. Interestingly, the reinforcement rings are not perfectly circular, instead they have one portion which is narrower than the rest and is designed to provide visual clearance where the rings would have covered up the serial numbers stamped into the towers. Another point to mention is that, because the new strut mounts are exactly the same size and shape as the originals, use of the Dinan caster plates will be unaffected. All in all, a very well thought out package which I believe will completely eliminate worries about frame and strut tower deformation. Bravo BMW!