One other Karavan update. This trailer is designed for the Australian outback road conditions and typical driving speeds. Here in the US we have a lot more high speed freeways with speed limits up to 75mph. What I found was that at speeds of 70mph or more, if you hit irregular roads surface conditions that had dips or bumps on just one side the trailer would start rocking side to side and would not stabilize until you slowed down. This is not your typical horizontal sway improperly weight distributed trailers can get into, this is a vertical side to side rocking on the independent suspension.
I worked with Kimberley on this problem and they sent me a beefier adjustable 18mm anti sway bar which I installed before my last trip. Success!:victory: The new stiffer anti swat bar totally resolved the problem. I was able to take it up over 70MPH on uneven road conditions even passing semis and getting the wind buffeting with no side to side oscillations at all. The trailer immediately stabilized after every bump.
I prefer not to tow trailers that fast anyway but if needed I don't want to worry about a stability problem. Bottom line is the new anti sway bar fixed the issue and I'm happy now.