One comment... When the player boots in AC mode, it goes instantly to the assigned visual, but in DC mode, it flashes through a few screens really quickly before switching to the visual. This is expected behavior, due to the nature of your fix, right?
Actually it's much simpler than that. In AC mode the player doesn't bother to switch to Track info mode because it's assuming you're not in your car while you're on AC power. The whole reason the player switches to Track info mode is to make the user explicitly turn on the "distracting" visuals, thereby absolving them of legal responsbility when someone runs their car off the road whilst engrossed in a Hula Hoops-induced trance.
So we are only concerned with switching info modes if we're in DC mode. In AC mode, the info mode will already come up correctly.
Sadly, there seems to be no easier way to switch to the correct info mode besides faking some IR presses. At least none that we've found yet... Someone who is handy with GDB and a hex editor might be able to locate (and possibly skip past) the code where the player does the info mode switch, but that would be a hefty assignment... Borislav, are you listening? I would think doing this would be similar to the unsorted menus hack... And it would provide a lot of benefit... The hijack solution is, in my opinion, less than ideal (though effective.)