I know anti-sway bars have been discussed ad nauseum on here, but I always thought the rear antisway bars on the Z was 21mm. I bought some urethane bushings for my anti-sway bars and according to the catalog, all Zs had 21mm rear bars. I measured mine with vernier calipers and its 19mm+ (something like 19.7mm). Did the roadster come with a smaller diameter rear bar?