Outside your first hideout is a small parking area to park your vehicles and save them. Instead of parking your vehicles fully within the lines, you can park your vehicles partially within the lines to allow for more vehicles to be parked and saved.

At the start of the game it would appear that you can only save two vehicles parked in the "Residents Parking Only" parking spaces in front of your safe house. However, if you can find other "Residents Parking Only" places around the city, you can also save vehicles there even if you do not have a safe house at those locations yet.

If you attempt to use the trick to keep more than two vehicles in any one parking space, it will only work until you leave the current game session. If you shut off your system, play a multiplayer game, or load your most recent save, all but two of your vehicles will have disappeared. It seems to either save the two vehicles closest to the center of the parking space or two at random.