National Interstate, part of American Financial Group, is updating its Open Road Classic Auto Program in Michigan, introducing revised policy language and a new endorsement to expand coverage and clarify terms.

The filing, submitted April 6, 2026, reflects a form update to the antique auto program, with changes effective upon approval. It follows a prior filing and is paired with a separate rate and rule submission.

The update centers on a revised Michigan state endorsement that modifies liability provisions, exclusions, and claims handling. The policy clarifies minimum liability limits in line with state requirements and adds up to $3,000 in additional property damage liability coverage in certain cases. It also updates appraisal procedures, expands duties after loss, and revises cancellation and nonrenewal terms.

The filing introduces a new Open Road Enhanced Protection endorsement, adding supplemental coverages and higher limits. These include fire department service charges, newly acquired property coverage, trip interruption expenses, and expanded protection for collector vehicles, including spare parts, personal effects, and VIN fraud-related losses.

The insurer also clarifies the glass deductible waiver, specifying that it applies only to standalone glass claims. Standard deductibles apply when glass damage occurs alongside other damage.

The program remains focused on collector car owners, requiring policyholders to maintain a separate primary-use vehicle insured under another policy, reinforcing its role as specialty coverage.

As background, OpenRoad recently announced that its classic and collector car insurance product is now available in 35 states, alongside platform upgrades to improve quoting, binding, and policy management for agents and customers.