Planenut will maybe correct me but I don't believe there are any post 2014 chassis which have lower wishbone bracket cracks.
I agree with you Chris, no need for the modification to the lower front suspension point on post 2014 specification chassis. As far as I am aware there have been no chassis cracks in the two known positions on any post 2014 chassis cars. Some early manufactured Brooklands M3W's were made with pre 2014 chassis, as you say they were made from September 2013 so they would be.
I would be interested to hear more about just what the problem was with M3W55's car as I have not heard of cracking in the post 2014 chassis before.
