I've driven by it a couple of times.

It's a brand new port and hopefully you shouldn't have any problems. You will need to do a temporary importation of the vehicles, see
here for details.
Port Tanger is just underneath the second 'r' of harbour in the map below. The motorway from Port Tanger running southwest towards Tanger and the Atlantic coast is now open. In the other direction there's a four lane highway running over the mountains towards Fnedq and Sebta (Ceuta).
Tim