Hello Bill, I sent you an email regarding this post.I use BCR shocks on my Solstice coupe which is set up fairly stiff and runs more power than the Z4M and have been very happy with them. If I need new shocks on my Z4MC (may be awhile - I am at 50,000 km), they will be what I put on that too. You can order them with the stock setting springs or custom stiffness.