Decided to make a list of the plates we found so far cause I don't think there are much more left that are not random. Anyway it in the first post of this thread.
Yeah, just pull down on the Right Analog Stick. Or, you could crouch behind the car and pan the camera as close to the car as you can, or if it's in a garage, use a weapon to view.
Drive around and there are many different personalized license plates, I once stole a blade that said "old skool" on the license plate, I thought that was cool. Weirdest one was a black washington I stole it said "EVEL 666" or something along that.