The great thing about small dogs is that you can take them a lot of places a large dog would not be welcome. Your Malamute may not be welcome at your grandmother's apartment, but your little Yorkie--maybe! This means you'll need to be able to take your small dog safely in the car to transport him or her around.
Good behavior when traveling in the car is critical, no matter what the size of your dog. A dog that is jumping around when riding in the car, instead of sitting quietly, is distracting for the driver and can cause an accident by interfering with steering or getting under a driver's feet, which are needed for operating pedals. A large dog is not as likely to want to crawl on your lap while driving, although there are some exceptions, we're sure. However, a small dog that is accustomed to sitting on your lap may think that it's a perfectly good place to spend a car trip. Small dogs must be trained to sit quietly in their designated spot and not on your lap, where they can interfere with your ability to operate the motor vehicle. Also, you want your dog to stay safe; a dog that is jumping about freely in your car can become a projectile if you suddenly need to brake. By teaching him to sit quietly in his spot, and possibly use safety restraints when riding in the car, your small dog will be a lot safer while motoring.
You will need to have treats to reinforce sitting behavior, and possibly engage an assistant to provide treats while you are driving, until your dog has learned to sit in the car when traveling. You can also provide chew toys for your small dog to keep him entertained on car rides while sitting in place. There are many car safety restraints to help keep your small dog in the correct spot when traveling and protect him in case of an accident. Car safety devices may help in training your dog to sit in the car and provide much-needed protection. Options include barriers that attach between front bucket seats to keep your dog in the back seat area and cushion him if he should fly forward in a sudden braking situation, harnesses that your dog can wear that attach to seat belts to hold your small dog in place when traveling and will restrain him in case of an accident, and doggy car seats specifically designed for small dogs. These car seats provide some protection with high sides to cushion your dog and raise him up so he can comfortably look out the window. These car seats also provide some containment for your small dog to discourage moving about the cabin during driving and in case of an accident. If you are planning on traveling a lot, getting your small dog one of these devices may be appropriate for your dog's safety and to help him learn to sit quietly in the car.