One of the most common ways of transporting your bikes by car is with a bike carrier for tow bar. For example, with this type of bike carrier you can transport 4 bikes, 3 bikes or 2 bikes. You can also choose to transport your bikes on the roof of your car. You can often use several bike carriers for your roof side by side to fit more bikes on your roof. A roof rack is quick to mount and often compact to store.