The 2000 headlamps do indeed work the same.
I was doing a little thinking about the parking lamps, and I think the
easiest way would be to install a relay. The park lamp switch provides
ground to the park lamp relay, which energizes the parking lamps. The
ignition switch provides power only. So, I was thinking about this:
Wire a relay into the system. Wire the coil side to ground and an
ignition only feed from the ignition switch. Wire the switch side to
ground and to the grounding wire from the lamp switch. That way, the
relay will perform the same function as the park lamp switch, and it will
occur whenever the ignition switch is in the "on" position.