Interesting topic. No doubt the fear of one's own new/young driver is freightening. I believe there are devices now that just monitor the car, speeds driven and where it went that you can just hide in the car.
A device (any) that messes with car's OE wiring worries me right up front. Just what is safe for a device to do if in fact it thought (mistakes happen with devices!) it was going too fast? Would you want the engine to shut down or just what or how would you have it do something? I'd be afraid of all this good intention being the cause of an accident.
Parental/Guardian control of a young adult has been a challenge for all time. Do your best,
T
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Tom Greenleaf - MetroWest, Boston