Simplistic New Beetle

Though The Beetle was in the list of my favor, she disappeared immediately after recognizing the rear axle construction, abhorrent torsion beam suspension was invited in spite of the 4 link with sway bar layout for Golf.

The importance of prevention in unnecessary lateral displacement of rear axle construction spoils the steering response apparently, this is ascertained by myself with some experiment on EP82 TOYOTA Starlet with 3 linked rear suspension.
Several hardness of rear lateral arm bushes were tried actually by myself and I had obtained indispensable datum at that time recognizing the importance of the supports of lateral force by rear axle construction.

Unfortunately NCP10 TOYOTA Vitz has the torsion beam rear axle construction, I tried to stop the displacement of rear torsion beam arm by applying special rubber part by TRD, resulting a bit effective but in vain. Muddy and sticky steering responding reaction could not be removed so far as the lateral displacement of rear axle construction remains.

However harder the attentions might be paid on the compliance in the steering linkage, frontal suspension arm bushes and geometric constructions, the signal applied on the steering would be easily consumed by the lateral movement of the rear axle. So the prevention of rear lateral movement must be more important than the reinforcement of steering mechanisms including reduction of tire profile.

Remember here the Natural Law, Stress is concentrated mainly on the weakest portion. The importance are the stress distribution and the establishment of some adequate compliance for a human natural reaction.

The test driver in the factory exerts himself in the efforts how much and where the compliance should be as a total balancing, ordinal user cannot follow after him, there are the apparent difference between a professional and layman.
Writing like this, the tendency caused by a fundamental constructive design like torsion beam axle cannot be changed the character however harder bush might be applied on hinge portion, because it does not have the important lateral force support from the beginning.