Your poor doggie, I hope some of the advice offered in the comments are helpful. It's no fun to have an overly agitated pet in the car. I have no good advice to offer as I have no dogs (I'm more of a cat person), but sending good vibes to you and your pooch.

What great news that your brother is moving closer to 'home'. That must be very exciting and happy making for both of you. Love that you'll be able to visit more frequently and hopefully spend a lot more time together (as long as you all get along, lol).