To acclimate your pet to traveling in a car, you can start by taking short rides to familiarize your pet with the experience of being in a moving vehicle. Begin with shorter trips and gradually increase the duration to help your pet get used to longer journeys. Make sure to use a secure and comfortable carrier or seatbelt harness for your pet's safety. You can also associate positive experiences with car rides by offering treats, toys, or praise to help your pet feel more relaxed and comfortable during the journey.