Weight distribution in a vehicle

Driver's weight in a vehicle affects on the wheel alignment at unignorable amount, it is said on Semi-Trailing Swing Arm construction in rear axle designing like my VW Air-cooled Beetle 1302. The degree of changes is so horrible as not to want to measure actually.
Scaling, Datum sampling and Adjusting procedures should be done in the condition of actual driver's in addition partner's weight on the seat promptly. The lighter the vehicle's weight is, the more upper tendency becomes apparent.
In another words, any procedure has no meaning if it is performed in empty car conditioned because of the reason mentioned above.
I make it a rule to prepare 3 of 20 L Poly-cases and put them on the driver's seat and foot position in order to reproduce the actual driving condition whenever I check wheel alignment and axle construction.
I spent not a short period of time to study this simple scientific principle, outsider like myself has difficulties to cut into some unknown field like getting into thorns road. But, the endeavor to carry out something would be always rewarded, tremendous information would be obtained on the way, even if many failures should be repeated.
Curiosity and interest occur because it doesn't go well, on the other hand, if it goes easily and successfully, there is no way to find out any pleasure at all.