are likely violating underwriting rules with both companies. If both are personal auto insurance policies in the same state they likely don't allow you to have 2 different policies. Most application will ask the question, "do we insure all vehicles in the household?" If you answer no to that question nearly all companies will deny coverage. There are specific legal reasons why they don't want you to have 2 insurance policies that can potentially cover the same claim.

Examples: You rent a car and have an accident. You are hit as a pedestrian. You exceed your liability limits on a claim for a specific vehicle.