If anyone really wants one, I can give a how-to. I used a sheet of aluminum I got from a friend for free, but you can pick up a piece at Lowes or wherever. I had some self-tapping sheet metal screws, a pair of snips, a jigsaw, and a blind riveter. I just made a cardboard template and then cut the aluminum from that. For edges I used the snips, and for the hole I screwed the sheet to a piece of plywood and drilled a pilot hole, then cut it with a jigsaw. It makes a nice, clean, round hole. I'm sure with a little more time it could be very nice looking, but you'd have to make a bunch of templates before you got it to really fit snugly against the wiring harness. I'll take a picture when the silicone cures and I trim it up. The insulation is on now so the top looks good, and it seals very tighly. I'm going to get a temperature sensor and test it out next weekend - data will be posted!
