Agreeed.... prep, prep, prep.
Wiper blades, belt, brakes, shocks, tires, lights (brake..reverse...turn...headlights), etc.
Make sure to bring a recovery kit (shackles, straps, boards, gloves,etc...)
Med emergency kit (basic small one)
Air comp, tire patch/plug kit.
One c/v shaft. Two ujoints. One main c/v for front prop shaft/w c/v grease.
But number one thing above all else have a good time and think / safety.
You can can actually fit all of this neatly in a low profile Rubbermaid kinda container. Drill holes in the lid at each handle and puta hvy duty zip ties through it. Don't want a back up part or recovery item hitting your head.
I've not been to Rubicon but have headed down to Indiana at that offroad park. I made absolutely sure to come prepared when my girl and I went. We stopped at a wally world and bought a bicycle orange flag on fiber glass pole. Got to be able to be seen.
Duct tape and zip ties. Lol!