An insurance company can promise you that they will payout a BMW to a third party based on your contract.
But that third party is not part of the contract between your insurance company and you, not privy to the contract. So he can't sue for a BMW.
Are you going to insist on the insurance company to payout a BMW to a third party, to the point of suing insurnace company of breach of contract for not paying BMW to a third party?
Possible but not probable.