I go through more than a few traffic "roundabouts" just about every day. For those that don't have these fender-bender loops, you do a fairly hard right to enter the roundabout, followed by a left bank around it, then another fairly hard right to peel off the roundabout. The quick succession of right-left-right is just great for inducing body roll.
When I first bought the truck, it really body-rolled on the roundabouts like a boat in a tight turn (though leaning out rather than in, of course). New shocks helped a tiny bit, but poly bushings on the front sway bar killed a lot of roll, and the ORD steering brace also killed some swaying.
I can go through these things now at the posted speed, feeling stable, and without appreciable body roll. Being beefy enough to discourage most vehicles from pulling right in front of you helps a lot in this circular ballet, and little cars get cut off all the time by smaller SUVs and minivans. A K5 isn't an F-650, but it looks like too much potential collision damage to your new minivan to risk a bump.
If it was mostly a wheeler truck, instead of a 99% DD for me, I'd consider ditching the bar, but those roundbouts would be mighty wallowy without a sway bar.