IMO,
and the SPCA's, in every case it is not a good idea to leave a dog in the car. Just like you would not leave a child in a car because something COULD happen.
However, if you do and the dog is in any kind of distress, including barking, howling, crying... you should expect that someone WILL call the police who will break the car window, (which will certainly add to the dog's anxiety) and remove your dog from the car, your dog will be sent to the local shelter, and you will be required to pay a fine before getting your dog back. (not to mention the damages to your car)
Depending upon where you live this could be considered an act of cruelty, neglect and/or abdonment, AND if this went to court you could not only lose ownership but be prevented from owning any animals for however long the judge rules.
Don't risk your fur-baby, leave the dog at home where he/she is comfortable and familiar with the surrondings
. Have a freind or neighbour check on them or hire a dog sitter. Your furry friend will happily greet you with tail wags and kisses when you return.
