The realization of wire routing through the wing spar bulkhead is starting to come alive and I need one more small hole on the right side for antenna wire. I've got the VOR antenna out in the right wing and the Comm antenna on the right side both behind the spar. So I read the supplemental write-up Van's has prepared for making additional hole. You are allowed to make up to 2 holes, one on each side. I needed only a small hole for a single RG-400 cable. The drawings say keep it as close to the center line of the spar as possible and watch out for hitting other things like fuel lines, wires, and other lines.