Quick answer
Through a specialty agreed value policy, separate from your regular auto insurance. You and the carrier settle on the car’s value up front, so a total loss pays that agreed number rather than a depreciated actual cash value. Most policies come with mileage limits and exclude commuting, racing, or commercial use.
We cover the specific tradeoffs, mileage caps, storage requirements, transit coverage, in our full guide to insuring classic and collector cars in Ohio.