Read this quick tip on how to get free car upgrades on Grand Theft Auto Online. Minor spoilers follow.
Simeon’s first mission will be at LS Customs. You get several free vehicle upgrades there, but only on a one time basis. When you actually enter LS Customs, you can’t leave without applying for the free insurance. If you want to get a car upgraded, this is the time to do it. Get the car you want and then do Simeon’s LS Customs mission.
Easy-peasy, and it looks like this one is not a bug, although it could get changed later. Share it with your friends!