There are a few other items like higher fenders, larger stock tires, electronic sway bar disconnect, and a few other items come included with the Rubicon that are options on the S; but far and away the most expensive/hardest to change item is the 4:1 low range transfer case. The price difference between the Sport S and Rubicon is about $5k. You should be able to do everything after market but the transfer case and come a grand or two ahead; so you have to decide if the transfer case (and a few other items) is worth it.