Unstable rear axle in Super Beetle

The performance and stability of VW AD motor equipped in 1302 Super Beetle recovered probably almost and utmost condition with some vigorous and aggressive reaction in any phase.
Now the complaint on my Beetle occurred in the rear suspension, no sort of vague, deformable with viscoelasticity arm supports.
This kind of deformable hinge material brings dull and muddy steering reaction, especially very beginning stage from centric steering position. Delayed reaction like this may cause driving fatigue.
New application of rear sway bar and trailing arm bushes in and out may improve the desirable stability leading to some steering reaction astringency.
Problems comes out one after another as usual.