How to stop your dog from fearing car rides? It is not unusual for dogs to be afraid of cars or car rides when they are first introduced to them. You have to teach your dog to trust the car.
You need to show your dog that there is no reason to be afraid to ride in the car. The best first step is to just sit in the car with your dog. Do not turn the car on though. You don't want to startle them. The point of this is to just let them see that nothing bad is going to happen to them by sitting in the car.
When your dog gets comfortable just sitting in the car, try turning the car and the radio on. If they get uncomfortable with this, turn the car back off and spend a few minutes petting them and reassuring. When they calm down, turn the car back on again. Once they seem calm with the car being turned on, take them for a short ride and talk positively to them while driving. Take them to a place they enjoy such as the park. Show them the positivity associated with being in the car. DO NOT take them to the vet on the first few car rides. If they are feeling too uncomfortable the first few times, return them home (where they feel secure) and practice again the next day. Just keep practicing until they are comfortable in a moving car.
Once your dog gets comfortable being in the car for short distances, increase the distance at intervals. It is best to start this when you don't have a vet appointment for a while. You don't want your dog to always associate the car with negative thoughts.
After your dog gets comfortable with the car, you will see their eagerness to go on car rides increase.