Can police tell if you have insurance in NJ by scanning your license plate?

Okay I had a problem about car insurance... I am on my grandfather's motor  insurance  program- I dwell with my sweetheart. In my opinion I am the only person insured to travel the car...My partner's mother and step-father do not have a car rightnow and often occasions consult to access my car- I Have been allowing them to till it was taken to my interest which they might not be covered in that car? Does this mean I'd lead to something that occurred? Or might they? If another automobile was at-fault for your incident what could happen? Everyone know this works?
Is it inexpensive? Would you get support from your workplace? What is a good value?
I used to be examining an article regarding the Toyota Prius and it explained insurance is approximately $1400. Is that $1400 even a year or a month?
"I know that in case you have car  insurance  "I donot realize is  insurance   for guys more higher than women