I've heard the drowned Immobilizer horror stories and wondered if anyone has tried one of these.
Porsche Boxster & 996 Immobilizer Waterproof Case Enclosure
Looks interesting, but my engineering brain has a problem with the method used to seal up the cable ports. You essentially work a big wad of silicone sealant into the wire bundles to seal the box. So...the effectiveness of the seal depends on how well you work in the silicone, along with an assumption that the silicone will never dry out. I'm skeptical...
Alternatively, wondering if anyone has ever attempted to move the box from it's vulnerable location to behind the seat on the bulkhead, or maybe simply elevate it at it's current location. Obviously, making sure all your seals and drains are functional is the first priority, but coming from a military aviation background, I like to eliminate the potential for single-point failures, if you know what I mean.