In answer to an earlier post, my 2009 4/4 Sport came with the factory fitted Track Day Pack option and this included roll bar, 4 point harnesses (no conventional seat belts) battery cut off switch and a few other bits and bobs but did not include an LSD unfortunately.
Altering final drive ratios on the 4/4 Sport is a bit of a minefield. Sure you can get a livelier response with shorter ratios, but motorway driving will likely be a drone fest and fuel consumption will go up with little return in performance. I'm not saying it is a bad idea, just that there is much to consider before choosing this route.
