Define the itinerary. You will need to draw up an itinerary dependent on roads. Since roads criss-cross much of the world it shouldn’t be too hard to begin with but keep in mind the following challenges:
War-torn countries are never recommended; indeed, you may not even get into some of them.
Roads in developing countries and outlying regions of developed countries can be very poorly maintained, some may look like roads but are mere tracks, etc.
Some roads are non-existent between countries, over seas, etc., so you will need contingency plans such as boat travel with the car, or collecting another car after a boat or plane flight.
Roads are weather-dependent. You can’t drive on roads that have been iced over, washed out or flooded. This means taking the seasons into account.
Be realistic. Unless you’re a millionaire or a person of few needs, you won’t be traveling the entire world by car in one fell swoop. In fact, you’d be lucky to be to achieve that in a lifetime even as a multi-billionaire. You will need to plan for a lot of time to achieve your goal and in all reality, you should select only certain specific trips that will take you to places in the world that really matter to you. When traveling by car, the world is a very big place.
Take the traffic tolls into consideration and learn when there are times to avoid certain roads, such as during peak hour traffic, during vacation seasons, during festivals or religious events, etc.