What happens when you do not hold the wheel?
 

My brother in-law is looking for a vehicle that will come to a safe stop if he were to lose consciousness. I know after 10-15 seconds of self steer, the warning message appears, and a bit later a buzzer sounds and seatbelt tightens up. I have never gone beyond that point. Does anyone knows what happens when the wheel is not touched. Car pulls over and stops, stops in street, warning goes off and does not self steer...?

Here's what Audi writes about it:

Emergency assist

Emergency assist detects, within system limits, when the driver is inactive. In such a case, the system assumes control of the vehicle and automatically brakes it to a standstill in its own lane. Emergency assist monitors the driver’s steering activity. If it detects that the driver is inactive, it prompts the driver repeatedly, via visual and audible warnings and by brake jolts, to actively take over control of the vehicle again. With the first strong brake jolt at a driving speed below 80 km/h (49.7 mph), the hazard warning lights are also activated to warn the surrounding traffic. If the driver remains inactive, despite the warnings, Emergency assist brings the vehicle to a standstill within system limits. The parking brake is engaged. The driver can deactivate Emergency assist at any time by moving the steering wheel, pressing the brake or accelerator pedal or by shutting off active lane assist or adaptive cruise control.