I don't think anyone is thinking of training on GTA then reusing it on a real car. It's just a convenient way to work out the algorithms and architecture in a controlled way that might then work out with the real world data.

But I do think GTA's unrealistic physics engine[1] will hurt it for simulating the cases we care most about (accidents, lost of traction, etc)

[1] GTA is a regular submission on /r/GamePhysics which collects funny game physics glitches: https://www.reddit.com/r/GamePhysics/search?q=GTA&sort=top&r... https://www.reddit.com/r/GamePhysics/search?q=GTAV&sort=top&... https://www.youtube.com/channel/UCy332GE6lcMVP612IUs7ODw/vid...