The alternative to a kill switch Scott is to hard wire a CTEK battery maintainer lead and route it through the access hole into the cabin. I've done that with my cars and have the connector close by the front trunk release handle where it is easy to reach and connect to the CTEK unit. The clock draws very little current but the CTEK certainly helps keep the battery in good shape when stored.
Current: F50, 246 GT (x 2), 246 GTS
Past: 360M, F430 spider, 430 Scuderia, California (x 2), 458 Italia (x 2), 458 spider, 246 GT