Would one of your service dog vests be suitable as a safety belt harness?

Would your service dog vests work as a safety belt type harness? I can see this would be handy when I hike our farm up north, especially in orange. The handle would be perfect when we stop to talk with neighbors. I use a SAR harness now for that. Although I know it is somewhat controversial not to crate a dog in the car, I want the contact with my dog and the security she provides by her presence, so I buckle her up when we drive somewhere.

Thanks for your advice!