There appears to be a problem with today's Grand Theft Auto 5 Title Update. According to players, and acknowledged by Rockstar, Title Update 1.28 is making vehicles disappear in GTA Online.
Though the issue was first brought to attention on Reddit, Rockstar has since acknowledged the issue, writing on the Rockstar Support page:
"We have found that some players’ garages may have been rearranged after updating to 1.28. If you think a vehicle is missing, try calling your mechanic and scrolling through your various garages to see if the vehicle was moved to another location erroneously. If you are unable to find your vehicle, please submit a request to our support team and we will assist you."
In some cases, if the car is not completely missing, all that is left are the tires. It's unclear how widespread the problem is, or if it's limited to a particular version of the game, but we'll continue to monitor the situation. It's a weird side effect from an update that otherwise fixed and addressed a ton of other issues across all platforms.
Accompanying today's update was part two of GTA Online's Ill-Gotten Gains summer event, which brought a ton of new items to spend your GTA$ on.
