The Thuren rear track bar is almost a required in IMO,the description of what it does on his site is accurate.
"The rear track bar equipped 2014+ 2500 Ram and Power Wagon has some strange handling quirks at higher speeds, mostly noticed on longer rolling bumps and dips in the road. Our rear track bar kit vitrually eliminates that wiggle, and transforms the truck into a very precise handling vehicle. Most gains will be felt on trucks with our softer rear coils. Compared to the OEM configuration our kit relaxes the arc the rear axle travels, reduces bushing deflection, and eliminates un-even torsional spring rate provided by the OEM track bar bushings. These improvements work together to reduce rear steer at higher speeds, fine tune the roll center, and reduce spring rate inconsistencies when the suspension cycles. While not a mandatory part needed for our suspension, most people find the upgrade VERY worth the money."