A normal push of the starter was required. A longer push or a holding of the start/stop button was not required.

I did not expect the vehicle to automatically switch into park, when I switched the vehicle into neutral. I performed all tests at low speeds.

It switched into park at probably 2 miles per hour, so yes it was an abrupt stop.

At a higher speed, it could have damaged the transmission. But, in an emergency, the viability of the vehicle is not a concern of mine. Shutting down the vehicle safely is. If that means destroying the engine or the transmission in the process, than so be it.

This all begs the question: will the vehicle shut off at freeway speeds? I do not know, but to me it's important to find out.

The latest fatality with the Toyota (I believe it was actually a Lexus, involved a family of four, with an off-duty highway patrolman at the controls. One family member called 911 in vain, as the car sped toward 120 miles per hour, before approaching a curve, and subsequently off a cliff killing all aboard. Apparently they were unable to stop the vehicle using the brakes, or any other options.)

I'm unsure as to whether they attempted to press the off button, switch the car into park/neutral, or take any other emergency steps, but one would assume they tried those things given the experience of the driver and the time they had to make 911 calls, etc.

So, in closing, I want to make sure that I'm able to shut off my vehicle at any speed, should an uncommanded acceleration take place.

I may contact BMWNA and see if I can get in touch with some of their engineers to see if they can provide me with some information.

I'm a bit hesitant to head onto a quiet highway, accelerate up to 70 mph. and then put it into neutral, given that it automatically switched into park. It could certainly be an ugly day for my transmission, in that case.

On the other hand, it's extraordinarily important to me personally, that I know that I'm able to shut down my vehicle in an emergency, at any speed, should there be a software glitch within the throttle control system.

Perhaps others can chime in here, but so far this is what I've discovered.

One other last ditch technique I discovered, is that opening the door and decreasing all pressure/weight on the seat turns the vehicle off/puts it into park. But, doing so at 80 mph. is not realistic.

One would think that simply applying the brakes at 90 mph. should slow the vehicle down, to a reasonable speed, but at full throttle, it's hard to say. I'd guess that you could probably wrestle the car down to 30 or 40 mph. using brakes alone, even at full throttle. At that speed, I'd feel comfortable (kind of), plowing the vehicle into a soft stationary barrier, in a last ditch effort. But, again, if it took place on a mountainous descent, it could still be a deadly proposition.

Given the speed at which the X5 accelerates, one really only has seconds to react in such a hypothetical situation, so again, I'd very much like to continue my experimenting and come to a conclusion one way or the other.

If there is not a way to cut the engine at speed, I'll likely install some sort of kill switch that will allow me to manually cut power to the fuel pump or to the ignition, as I'm just not a fan of any system that can malfunction to the point that I'm unable to manually override it, especially a throttle-by-wire system with an electronic start/stop switch.