For private use in CA there is no reason to register the vehicle at its full capacity AND PAY HIGHER FEES as you can just load it and go.
Once you come to vehicles 15k + that you use for towing, that is when GCWR comes in play. You have to declare max combo weight you plan to have and you will get square stickers that you place on the doors visible from outside.
On my F450 I had 30k stickers and those alone cost me about $400 a year.
It is all about tax money.
BTW all my Mercedes do have weight stickers on door pillar, so I wonder if Germans put them only on exported models.
