Okay, I've replaced the HDD cable and HDD to get those out of the equation, but the player still occasionally sigkills and reboots. Typically, the player is in Spectrum Analyzer/128 mode with the info line displayed on the bottom but I have tried other visualizations. After the player reboots, it's in 'Now and Next' display mode. I don't believe I've ever gotten a second sigkill once the player got into 'Now and Next' mode. When I turn off the car and restart, the player boots up into the 'Line' display mode like normal.

Anyone have any clues as to how to debug this? Again, the only thing I did differently was to try a v3 image and new Hijack several months ago. I'm back to the latest v2 but the sigkills continue.