Garagekeepers Coverage for Theft of Vehicle

Our insured is an auto dealer and has a garage coverage form with garagekeepers coverage. The insured has presented a claim for the theft of a customer's vehicle that was left in the insured's care for a consignment sale.

If the insured had physical damage coverage under symbol 31, we could see coverage for the consigned auto since it was held for sale by the insured under a written consignment agreement. But, the insured has physical damage coverage subject to symbol 28, hired autos only. Since there is no physical damage coverage for the stolen car, would the garagekeepers coverage apply? Are autos left on consignment with the insured covered by garagekeepers insurance?