IRS lateral displacement

VW1302 Super Beetle has been operated on IRS trailing arm bushes on both sides inner and outer and the steering action was far improved comparing with before operation. But, I'm not fully satisfied with this improvement because the very initial phase of steering action is still dull and muddy for me, this phenomena is not caused by the tire profile 80%, weak spring and shock absorber, narrower tire tread but the lack of the resistance to an inconvenient lateral displacement of IRS trailing arm. #70 JIS rubber standard 3mm thickness round doughnut shaped parts would be applied between trailing arm bracket and IRS bush outer end surface promptly. This method for preventing the arm from lateral movement is commonly used in some Motor Sports field, for example, TRD special parts for the purpose on NCP 10 Vitz Cup Races. The result of this experiment on VW1302 Super Beetle would be reported later.