Thrust angle adjustment on VW Air-cooled Beetle 1302

Thrust angle adjustment was successfully performed today on VW Air-cooled Beetle 1302.
Simple concept of triangle similarity with trigonometric symptom made it possible to calculate the adjusting distance on the rear right side trailing arm. 3.10 mm extension was the data obtained as a matter of fact. Trailing arm supporting point is important, at the position of the end of clumping point, not the external solid part, otherwise rear moving arm will goes up and the vehicles height becomes lower.
Naturally, Steering center position changes after thrust angle adjustment, because the former discrepancy on the thrust is compensated by front toe directional vector.
It was lucky the steering was re-positioned at the centric position by sifting one spline tooth.
My work these days are trifle I recommend so, but piled trifles is not always trifle, it merely be nothing but self contentment.
Recently, any vehicle user cannot enter the IA controlled system, so the adjustment I did is the only way to have some relation with the vehicle to being kind. Any machinery production contains the tolerance, so to speak "Range of specific error", I wanna make the assembly error zero as much as I can.
VW Golf GTI that my son is using has thrust angle error, within the tolerance plus minus 10 minutes, and he is going to sell it in the near future. 5 years use with only 25,000 km run at less than half price of purchase. His intention might be changed if I adjust the thrust error to zero? Or I would like to use it instead of him.
Anyway, as keeping a vehicle wastes money, so my Xanthippe says with mustache about that. Thunder always comes on me after a sincere comfort.