[el_benhameen]

I'm probably missing something here, but wouldn't it make sense for ONSTAR to sit on the drive critical bus? If it's able to monitor collision data and (in newer models) slow down a stolen car, it'd need access to drive-control systems.

[obituary_latte]

I'm unsure whether it makes sense in the context of safety. However, in the context of being able to sell the product as having those features - makes perfect sense.