Driving without a license is illegal, driving without insurance is illegal. Take the vehicles and auction them off in either case, no recourse.
Rosenbergs should sue the city for $100 mil or so, forcing them to repeal any ordinance that violates the existing laws. Every time the city fails to enforce, sue. Sue until they submit to enforcement. Demand a jury, the judges are politically motivated and refuse to enforce immigration laws, work requirements and every other Constitutional requirement that is inconvenient to buying illegal votes.