After sourcing and delivering a car, return to the laptop to start another mission. You just need a vehicle warehouse to get started. It's possible to run this business out of a populated friendly lobby but just search for an empty one if you encounter issues. RELATED: Best Pets In The Grand Theft Auto Series

Once the game recognizes you have ten of each in stock at the warehouse, you'll no longer be given source missions for them, allowing you to always source and sell the most profitable, top-range cars. Here's the trick - make sure to never sell your standard and mid-range cars. Importing and exporting cars is one of the most efficient businesses it's simple, can pay well, and players can stock up on their supercars.