
realy you all need to be on the same page with training or the dog will get confused. Id call a meeting and all sit down, list the problems and each of you explain how you would deal with it and why, then discuss why you don't agree or agree calmly and find a method you can all live with. If you still cant agree it might be worth getting a trainer in and get an outsider involved, they can observe your dog and listen to each of you and suggest what they feel is best suited for your dog.
What methods are you using and what methods does your husband want to use?
for the car I would move him to the back seat, strap him in it shouldn't be long enough to allow him off the seat, just stand and turn) and have a car guard across the back and by the front seats so no chance he can get anywhere then use towels to block his view out. Also id make sure he has had some good exercise before going in the car. Maybe even worth using something to relax him if its that bad.
At night maybe have a radio on quietly and stuff a Kong toy for him to keep him occupied, also a good walk in the evening and then some quiet time to relax before going to bed. That helped a young pup my brother had when they stayed up with it one week, poor thing didn't like being left in our kitchen at night.