Baloney!
We have an '87 31' and have run lots of new wires. To the pedestal (GPS, power), to the Yanmar control panel (oil pressure and water temp gauges), to the rear lazaret (speakers, power), to the transom (radio antenna). With a fish tape you can send any wire, anywhere in the stern from the port lazaret. Only problem is keeping my weight off enough to continue to escape from the lazaret when I'm done. (The Admiral is svelt enough but refuses to work in the lazaret)Yeh, for $100K or so you can get wire runs and a few other goodies. 31 foot Hunters are just as much fun and a whole lot cheaper. We cut up an old chunk of garden hose and made our own runs. (They don't show)We got oriented by following the stern light wire to see how it got around the water tank under the rear berth. It's pretty open under there once you start looking around. Good luck.