After a bunch of wrangling, I have fixed (hidden) the audio noise problems by using a ground loop isolator. With that taken care of, I started work on creating a proper trunk installation for the car PC.
I wanted everything to be easily removable, so I chose to build a shelf out of 1/2" MDF and hang it using threaded rods. I covered the shelf in black carpet to match the trunk, and mounted a bracket on it to secure the computer to.
Everything seems to fit nicely. The computer is secure, and the trunk is still usable. I'm debating removing the carpet and replacing it with black Veltex, which is the fuzzy side of Velcro. Doing so would allow me to keep the cables secure, while at the same time easily movable. The next step is for me to take some pictures, which I should have done during the install.
