The law is not that naive as you try to hack. Otherwise, everyone will go through the loophole.
// To remove your spouse from a joint car insurance policy, you will need to get their signed consent and then follow the proper procedure, which will depend on your insurance company’s rules. If you and your spouse are sharing a home, your spouse will have to get an auto insurance policy in their name before you can remove them for your car insurance policy. Your insurer may even require an affidavit from your spouse’s auto insurance company to confirm the policy and coverage information before removing your spouse from your policy.