The surface is pretty smooth. We all use a similar setup but I have changed a couple of things. Im using a combination of rear arm mounts to enable me to have pro squat in the rear using an 'A' front mnt and a 'C' rear mount. This angles the rear arms in a slope w the rear of the arm higher towards the rear. Also, in the front I have place a thin castor shim under the front bulkhead mount screw which gives me a touch of kick up. Other than that we all use the same other stuff. I'l just have to remove my 'mods' to see if the problem goes away. My car has been awesome w that setup but all of a sudden the car doesn't seem to like them anymore. Very interesting......