Nice post, good to see the dedication in refining the parts. I have one questions, now that there is nothing breaking except for say a rim, what stops the impact causing say the chassis to bend on impact. Being that the car has aluminum bulkheads fixed directly to the chassis. The plastic arms are design to absorb the impact and breaking is part of the job. Check the chassis, pull everything off the chassis and check for straightness. I am sure the chassis has a tweak in it.
I would have tough that replacing a few dollar item would have been cheaper then replacing the chassis.