Just pick up some money and your money should return to what it was. The reason it says you have negative four billion is because you used the pimp my ride NPC and it costed more to modify your car then what you had, glitching your money.

Just pick up some money and your money should return to what it was. The reason it says you have negative four billion is because you used the pimp my ride NPC and it costed more to modify your car then what you had, glitching your money.