Am reading the police report on a new case:

T told me he had a dog in the vehicle. I checked and located a brown lab type dog on the rear passenger floorboard. The dog was not breathing and I could not feel a heartbeat. I asked SFD E31 to check the dog too. there did not appear to be any signs of life in the dog.

We don't leave our children unsecured in cars for the same reasons we shouldn't let our dogs roam freely.  We may like to cuddle with them. They may be happy as they crane their necks out the window.  But the second that vehicle is violently struck; the dog will go airborne and almost surely die.

Use a crate, or secure your dog with a chest (not neck!) harness clipped into existing seat belt hardware.