Rapracing,
From looking at a parts diagram there are 6 parts common on top and bottom A arms, bushing part 040 K7591-1745-2, both top and bottom have a collar between the bushing, part 050-K7591-1866-3 lower and 050- K7591-1867-2 upper, can you tell whether it is the bushing wearing causing the play or the collar or just manufactured with too much tolerance?
Reverse engineering may be the only answer to solving Kabota's problem for them, measure play on a new one and then measure play on a used one with more hours and figure out which part is wearing too quickly or built with way to much tolerance to begin with., take the problem back to them with some evidence and possibly get further with it than a reply like "they are built this way to do it". Corporate risk analysis on problems that are potential safety and life and death which could happen even at 30 MPH top speed and the front end falls off due to wear of key components is not good for any of us nor them as a corporation.