There are 3 kinds of large wires traveling forward and back in the plane: - a positive and negative 4 AWG (welding) cable from firewall forward to instrument panel, - a 12-conductor expansion bus from firewall forward to instrument panel - a positive and negative 4 AWG (welding) cable from the shore power "Piper" socket to the firewall Wires are to be secured every 4 inches. In some locations I took that approach (see forward of the panel, where lines curve to the terminal blocks). In others I decided to make a cover - in the rear seat the lines could be kicked or shoved by a passenger. Below is how I molded a cover for use in corners. Other surfaces used different molding jigs and a similar process. A jig was made of scrap wood, whcih was then covered in packing tape. Wires/ cables of appropriate size were fixed on the board and covered with packing tape. Two lengths of BID tape were cut to the length of the jig and wetted out between two sheets of polyethylene. THe tapes were laid over the cables and edges defined by boards clamped or weighted during the curing process. When cured, the part was released, inspected, cut to fit and #4 screw holes drilled.