You need the panhard rod connected. It could cause some terrible problems at higher speeds trying to drive with it off. Nobody wants an accident.
Reinstall the panhard rod at the upper frame mount as normal, then weight down the back end with either some people or heavy items (at least 200 lbs), leave the hatch open (distributes weight outwards and more rearward) and and then jack up the center of the axle. Lightly grease, then install one of the cone-shaped bushing halves onto the panhard rod lower mount, then slip the bar's end over that and put the other bushing on top. Then tighten the nut and squash those bushings together. It'll straighten out by itself under normal driving. Lower it down and you're done. Re-check the lower nut later for looseness, just in case.