A car needs to be registered where it is "garaged", which is a legal/insurance term of art basically for where the car spends most of it's "down time", when your head is on the pillow.
Should that vehicle be involved in a motor vehicle accident, it is possible that the vehicle's insurer will perform an investigation and disclaim coverage based on fraudulent information in the insurance application. I have had clients come to me after this happens and it is most often too late to be of assistance. However, the owner of the vehicle which you reference is in the position presently to make the change.
This answer is provided for informational purposes only. Actual legal advice can only be provided in an office consultation by an attorney licensed in your jurisdiction, with experience in the area of law in which your concern lies.
Usually the question asked by the insurance company is "where is the car garaged"? If someone does not disclose the correct information to the insurance carrier, the carrier may deny coverage when it is needed because of the fraud in obtaining coverage.
Mr. Lundeen is licensed to practice law in Florida and Vermont. The response herein is not legal advice and does not create an attorney/client relationship. The response is in the form of legal education and is intended to provide general information about the matter within the question. Oftentimes the question does not include significant and important facts and timelines that, if known, could significantly change the reply and make it unsuitable. Mr. Lundeen strongly advises the questioner to confer with an attorney in your state in order to insure proper advice is received.