In two battery packs, I lost two front pins, one front axle, and one bone. Never hit a thing running with modifieds. None of those backed out. Then last weekend I had another pin snap, and lost the coupling and my last pin. I ended up cutting off the straight edge of a body clip to use as a pin. It didn't break, but has alot of slop. I bought some RS MIP's for the front and tobee AL. bones for the rear. Should be nice and efficient for the US nats.