I have an Aussie and get some thumping as well. I've noticed that an Aussie will highlight any driveline noise you have, in my case it seems to be that my poly spring bushings need replacement and/or lube. When I spray them with silicone or white lithium the noise stops for a while, so seems the axle wants to wind up a little on acceleration and the bushings are creaking.
Another thing to watch is that your tires don't have slightly different diameters or inflation, this exacerbates the thumping, clicking, normalizing bangs and what not. When I take time to match the rear tires to a gnat's rear I notice that I extremely rarely will get that pit-of-your-stomach bang.
I personally take round-abouts and sharp turns with the clutch disengaged, it's a very refined skill. Accelerate a bit more than normal heading into and coast through.
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