Stock Class (BMAX) Rule Update
so there's another rule revision for Stock Class that got posted today. a new rule regarding restricted zones was added along with the current rules
The range enclosed by the front and rear wheel shafts and left and right bearings, as well as the range inside the outer edges of the left and right tires from the center axis of the front wheel to the rear end of the front wheel and the range inside the center axis of the rear wheel to the front end of the rear wheel (see diagram below), are designated as "prohibited ranges." With the exception of the driver figure, no parts other than the body shall be provided within the prohibited range. In addition, with the exception of the driver figure, all or part of the parts other than the body must not fall within the prohibited range.
With the exception of the rotation of tyres and rollers and the movement required by the function of mass and sliding dampers, any parts which come into contact with or may come into contact with the course wall or running surface shall be fixed to the bodywork or to a plate fixed to the bodywork.
looks like this is Tamiya's approach in killing the ball link lantern loophole from the current regs. rule 13 seems to be a rule to shut down any attempts at an anchor/AT bumper since it's still technically possible through ball link attachments.
source https://tamiya.com/japan/mini4wd/regulation_stockclass.html