What I've noticed is that after the 1st of Jan '06 the DRL, are the slightly dimmer headlights and the position of the GM Accent plate on the body is located higher on the fender, just forward of the doors.

The first '06 H3's which had the parking lamps as the DRL, also appear to have had the GM Accent plate located on the front door by the H3 logo.

I looked at the '07's, and they follow the same design as the later production '06's. FWIW.