While there may be no laws about ‘transporting it in the trunk of a car’, since our legislators can’t think up every possible inhumane thing someone could do to an animal, it would probably fall under ‘animal cruelty’ since it’s putting a live animal into an enclosed, non-ventilated trunk (a Malibu isn’t a station wagon) in the warmest part of the summer. Also, there ARE laws about keeping animals in cages, enclosures, carriers, etc, and the bare minimum is that the animal has to be able to stand up and turn around, neither of which an average-sized goat would have been able to do in that car trunk.
The point is, the goat was taken away from this woman because she was mistreating it.
The last time I adopted a cat from the local SPCA, they told me to bring a pillow case for the drive home. A dark, enclosed, space will cause the animal to remain calm during transport. While a cat isn't a goat, the behavior is fairly universal, I know for a fact it works on chickens too. I drive an '05 Malibu, and the trunk is cavernous, and while it wouldn't be appropriate for long term restraint, for a 30 minute or an hour drive, in Minnesota temperatures, ....not even approaching cruel.