BIC already has these available. I have tried Aluminum, Nylon and now I have a prototype poly set on my car. They reallly tighten up the rear suspension. The is no more "floaty" feeling when going over bumps at speed. The steering response is also alot crisper as there is no shifting of the rear crossmember. It is a great cure for wheel hopp, if you jack up your car by the body /pinch welds, then take a prybar and see how much the subframe moves up and down, there is at least 1/2" of play, when you get wheel hop the whole subframe is bouncing up and down. The one drawback is that you get more NVH (noise, vibration, harshness) with these, you hear the road more and if your diff is noisy you will really hear it with solid spacers.......check the BIC section for pricing and pics if you are interested.
Randy