I just finished looking for the OBD-II scan port (or Data Link Connector?) on a 2006 Chevy Trailblazer and a 2011 Chrysler 300. The OBD-II scan ports were not in obvious places on the dash like in the videos I watched, and the Chrysler's user manual did not even mention the port, so it took a bit of hunting to find. Both ports were underneath the driver's side dashboard on the left side of the steering column, hidden from view unless you look up from below.
The Chrysler's port was on the far left near the door, relatively close to the seat. The Trailblazer's port was closer to the steering column.
(The Trailblazer's port also didn't actually work when I plugged in my scan tool, but the 300's port worked fine.)