car insurance two drivers

Questions car insurance in New Jersey?
My husband and I have two cars, both insured with us as drivers. However, his mother (and sometimes his three brothers) have been using my husband's car while it is fixed there. They have had the car going on three months and have read at progressive.com (our insurance, obviously) that we are responsible for ensuring that any "regular" drivers are covered by insurance. I'm not sure their insurance status, and that the car was so late in getting it fixed until they canceled it back. So we really do not want to contact the insurance company, I am sure we will do the best for them, not us. My questions are – we are responsible under our insurance cover as it was driving "regularly" or since we have the car is well covered? What if someone outside of me and my husband had a crash in which car insurance to be obsolete?
Your insurance coverage is fine. What do you mean a regular basis is that the person driving the vehicle uses the vehicle as their only source of transportation. If family members are just car loans, for theirs is out of service that you are well. There is no sense in ensuring all members of the family for a short period of time. Had an accident and your car (always driving) is at fault then your insurance coverage remains valid. While the driver had permission to be covered to drive your vehicle. Do not worry, you're well
Stupid Geico Commercial with Talking Pipes