By adding ramps on a paracer platform saddle, you can exploit a glitch that makes the elemental's weight not affect the paracer. You can use this to gather massive amounts of materials. (Have one person drive the paracer, while someone else rides the elemental and harvests)
Rock elementals are extremely tough to kill or knockout. Over encumbering them inside or around your base and setting them to aggressive allows them to defend your base with their rock throw attack without being kited away by enemies.