SUPERBOWL XLVIII Issued in late January, these plates were for use by Superbowl vehicles.
They expired on February 12th, 2014.

Read the MVC Advisory about these plates.
   
These plates were not spotted on the road - but they were apparently used.   These plates are flat.

Mockup from NJMVC
New Jersey Superbowl XLVIII License Plate

Picture of actual plate from Paul Rosenberg
New Jersey Superbowl XLVIII License Plate

J. MattesFrom East Rutherford FD
New Jersey Superbowl XLVIII License Plate