It seems that the 1.06 patch for Grand Theft Auto V has opened up a glitch in the Grand Theft Auto Online multiplayer that allows players to exploit it for unlimited money.
The exploit centers around character switching between online and Story Mode and selling a car to Los Santos Customs.
The steps:
1. Steal a car and drive it to any Los Santos Customs (LCS)
2. Once at LCS, upgrade your car. Make sure you insure and place a tracker on it
3. Spawn outside LCS and park your vehicle anywhere around the building
4. Go to "Options" and set Spawn Location to "Last Location"
5. Leave GTA Online and switch to Story Mode (single player)
6. As soon as you spawn, start a new game (this will create a new Story Mode save)
7. Once the new game starts, go back to Play GTA Online and enter an Invite Only session
8. Go back to your upgraded car if you aren't already in it when you spawn and drive back into LSC
9. Sell your fully stocked car and as soon as it says "Sold," press "Start" - "Online" - "Swap Character" - and click on your character
10. You should spawn back outside of LSC with your upgraded car still there (along with all of the money you just made!)
11. Repeat from Step 5 for unlimited money
It should be noted that gamers who exploit a glitch usually get hit with the banhammer pretty hard regardless of intent, so use at your own risk.