In Puerto Rico, cars rarely have license plates on the front. There is also an antenna on the front of the Google car in Puerto Rico, whereas it is almost always on the back or not visible elsewhere.
Plates
Front plates are very rare in Puerto Rico. Rear plates are white with black lettering, and a light green strip along the bottom.
Car metas
The biggest tell for Guam, Northern Mariana Islands, and Puerto Rico is the large antenna on the front right corner of the camera car.
