Important subjects

Tons of articles in relation with Wheel alignment and Axle construction could be obtained through Web site now.
The most important thing to discuss with and to do on the same page is "Unification of definitions" and "Equalization of measurement conditions".
In spite of the absolute condition and requirement, most of the article about Wheel alignment lacks them, especially in Scientific field, an article with any inadequacy is not evaluated, remember this description is some common sense at all.
Load point and it's weight, driver's body weight only or with navigator's one, some times burdening weight including residual fuel amount.
Positioning 60 kg weight wile wheel alignment scaling and adjusting is the specified requirement by German OPEL AG. for B-Vectra in the maintenance information.
It is true that the preparation seating the weight on the driver's seat while scaling and adjusting the axle construction is the matter more important than nothing. Otherwise, desperate efforts with muscle work comes to in vain, unreliable datum are the litter however piled they might be.
Another barrier is troublesome physically property of rubber materials those are scattered everywhere in the axle construction of a vehicle as compliance designing. As we know, they have elastic strain and hysteresis, including tires themselves.
Once a construction part is moved, the influence is propagated not only this portion but another 3 wheels, there exist hub bearings containing backlashes for grease lubrication, they are also affections on the result.
Avoiding such kind of artifacts and the influences, scaled and adjusted car should be moved forward and backward in every scaling and adjusting, just putting the car on the alignment tester and adjusting is far from precision.
Moving a car on the place is harder muscle work more than  loosening and tightening 17-19 bolt and nut.
Because no professional helps me, I dare do it by myself.