Could not afford car insurance let car sit for a while-in a car accident in another vehicle as a passenger-No Fault State-get into trouble for not having insurance the leased car that sat?

This depends on the state. For example in PA if you have a vehicle registered but do not insure it, then your medical claim will be denied. In FL your insurance covers your injures regardless of fault and regardless of the car your in. If you are injured as a passenger in some one elses car your injuries are only covered by the owners insurance if you do not own a vehicle.