If you have to spell out the word C-A-R or R-I-D-E, your dog is probably overly eager to go with you. On the other hand, if you are pulling your dog by the leash to get him into the car, you may need to spend some time working on teaching him to enjoy going for a ride. Getting in the car is necessary even if it's only for veterinary appointments. But there are probably other places you will need to take your dog, whether it's to the groomers, for boarding, to a dog park to socialize, or to puppy training classes. The number of times you could potentially have your dog in the car is endless. If your dog doesn't enjoy being in the car, it could be because he feels ill, he may not be used to the motion, or he's not sure what to do while he's in the car and unable to be close to you.
Teaching your dog to like car rides is about making him feel comfortable and repeating the process, so he knows that he is safe and you are with him. He will also know if the journey is not fun, at least there will be a reward at the end of the trip. Turn your car into a place your dog would like to be. Keep a soft blanket on the seat where you would like him to sit. Take his favorite toys with him, so he has emotional comfort as well. Be sure to make your car safe for your dog, whether you are using a harness and the seat belt or a dog carrier, depending on your dog's size. If your dog is anxious because he feels sick, you can lift him higher with a seat or a crate, so he can see out the window. Preparation before going on a car ride with your dog is key. If your dog is truly afraid of being in the car, you will want to take short trips before you move on to a long-planned trip.
To get started, you are going to need a vehicle your dog can be safe and comfortable in. A blanket or a chew toy, or even both, to take with you would benefit your dog. A leash and/or a harness for stops will be imperative, so if your dog bolts when open the door, you don't lose control over him. And be sure to have lots of treats handy so you can reward him for a job well done.