Remove Vehicle. You don't want to discover the significance of antifreeze by being forced to pull over, due to an overheated engine. Antifreeze contains lubricants and anti-corrosion agents to keep components like your radiator properly lubricated and free from corrosion.
Fear, Pain, Excitement. Your dog may shiver due to fright or excitement, an occurrence common in smaller or excitable dog breeds. Some dogs tremble when they encounter other animals, or if they have a form of anxiety in which meeting other people makes them overly anxious. Loud noises ranging from thunderstorms to vacuum cleaners and power tools can also frighten dogs to a point of shivering. Shivering can also be a sign your dog is in pain.
The end result is an even more freaked out dog because he has learned he will get attention when he freaks. Try to ignore the theatrics tonight, and say nothing. Shaking and shivering is a normal, panic attack reaction the dog must go through to learn he really can deal with the noise. A little pat here and there when the dog comes to you is fine, but no talking.