The Cooper S is blessed with healthy power and a superb suspension from the factory, but the burden of mass damps the car's effectiveness. We could start with more power, grip, and stopping power, but our quest for MINI rightness pointed toward curb weight. Physics is on our side here; lightness improves performance in every direction while adding a nimble sense of fitness that a brute-force approach can't offer.


The most offensive pounds are on the roof. A massive, two-panel glass sunroof that spans nearly the entire length of the car puts a shocking 53 pounds in the single worst place it could be. Ordering a Cooper S without a sunroof is the wisest path for those seeking the rightest and lightest of MINIs, but when life gives you lemons, well, carbon fiber is the best form of lemonade.

Carbon Trix is a small spin-off of the Mitsubishi-tuning Road/Race Engineering empire. Its carbon-fiber bits are mostly small (scoops, vents, gauge pods, etc.) and usually backed with fiberglass, but even fiberglass-backed carbon fiber is vastly lighter than the MINI's depleted uranium sunroof. Most importantly, Carbon Trix is a lean, mean company willing to build whatever goofy carbon-fiber things people want to buy. Like MINI sunroofs.

The MINI sunroof has two panels, with the front one on tracks and the rear one glued in place. Carbon Trix took a mold of the entire thing, smoothed out the seam between the two panels, and made a single-piece replacement panel. Aerodynamic forces on a panel that large can be huge, especially at triple-digit speeds, so we had them make the panel extra strong, at the expense of some weight. The panel is the same thickness as the stock glass, allowing it to sit on the stock seal. Underneath, there are two large half-inch thick honeycomb sections, then one extra layer of fiberglass. The thickness added by the lightweight honeycomb makes the panel ludicrously strong. The thick fiberglass weighs about 7 pounds, and we mounted it to the 7-pound plastic frame that held the stock sunroof. We had the rear glass panel cut off by a glass shop, but using the stock frame let us use the stock seals and drain rails, which ensure whatever water does get past the sunroof doesn't end up on our heads. Total weight saved: 39 pounds. The panel has survived nine months of daily use, countless triple-digit excursions, and torrential downpours without a single problem.