On the wing mod I will probally just use a Blind Nut and Bolt on that to. With the way the wings are designed even if the plastic bolts were to shear during a crash, I believe the Wings would be pretty well destroyed anyway due to the hard Ply Spars being joined together by a hard bolt. The wings will surely bust before you bust a spar. The Only way I can see where the Plastic Ones would do good at the Trailing edge is if you used Plastic Ones with the metal wing nuts on the main spar also. Then you may get lucky and the plastic bolts would just shear in both locations instead of the wings being ripped to shreds due to the rigid spar.