Hi , When the dog is scared in the car it is best to take it in small steps.
First, what does he do when in the car?
What do you do or say to him when he acts upset?
What type of training in obedience has he had?
What commands does he listen to the first time you give them no matter where you are?
Thank you for that information,
When we talk nicely to a dog or stroke it at a time when they are most fearful it only encourages the behavior because the dog begins to think there is actually something to be afraid of . Humans want to help a animal as much as they can but we put our own emotions onto the dog when really if the dog was in a pack he would not get any attention from a pack member if he acted that way so they don't understand our emotions, but they can understand the tone in which they are said, so you are actually rewarding the scared behavior and not realizing it. Also if you are feeding the dog at a time when he is scared you are again rewarding that behavior.
What I would do is start slow, put him in the car but don't turn it on, do this for about a week, keep the time brief, then take him in and start the car but don't go anywhere, ignore scared behavior praise good behavior, keep yourself calm so the dog remains calm, then after that week is over start the car and go down the driveway for a week, and then take it to the street, short trips at first, then go longer and longer,. Stop the car at places that you can have fun with the dog so the dog soon understands that going in the car means something fun is going to happen at the end.
dog training consultant
24 years training & behavior,pet first aide, Therapy dog eval., PA Animal Response Team