Reply To: 2016 Q3 build challenge – derby cars Home › Forums › MOCs › Build challenges! › 2016 Q3 build challenge – derby cars › Reply To: 2016 Q3 build challenge – derby cars July 27, 2016 at 11:12 am #17167 Tom FrostParticipant Nick Chen wrote: at Cranberry Twp I used pipe insulation and a styrofoam bumper to protect the cars. David H Donley wrote: Only Lego elements. The styrofoam, etc, was at the end of the track to catch the cars, not a part of the cars 🙂