Personally, as I'm living in a zone where only 30 km/h are allowed (because of a kindergarten and a school) and seeing every second car driving by too fast, I'd appreciate such a thing.
But where are you going to stop? We already have cars that won't start if you've drunk alcohol or if you haven't fastened your seatbelt. Will there be cars that won't start if it's below 0°Celsius and you haven't got winter tyres attached?
Why draw the line at speed limits? Get the GPS to stop your car at red lights, to stop it when you want to turn the wrong way into a one-way-street, to yell at you if you want to park in a no-parking-zone or to stop if you want to drive into a green zone without permission (that's a zone where only cars with a low exhaust standard are allowed - like in Munich). Let the car decide that the distance to the car in front of you is big enough.
Bankrobbers or other criminals won't be able to put up a car chase against the police, for they will be stopped by the GSP-speed-limiter. Oh, wait, my hubby says that it's just an electronic device and those who want will find a way around it.
Speaking of electronic devices. They tend to fail. We were in Munich last week and our Navigation-thing (which is working with GPS) always told us to turn around while we were in a one-way-street. Then it told us we were driving through the park, while we were on the beltway - allowed to go 60 km/h...
(Well, hubby also says: another thing that will be broken a lot, will cost lots of money to repair like most electronic fuzzy things in the car
)
I think it will get dangerous the moment people start to rely on those things. According to (german) statistics, most accidents happen because of speed not appropriate to the situation. Mind you, not driving above the speed limit (btw, we still have lots of motorway kilometers without speed limit - what would the GPS-limiter say to that?
), but driving too fast while the streets are wet, icy, snowy, whatever. Mostly young people go too fast, driving the speed limit, but not heeding the street condition. Like "oh, this street is limited to 80 km/h, so I'll go 80 km/h (although this bend to come is only drivable with 40 km/h)"
What if the car in front of you has GPS-speed-limiter and you haven't? You won't see brake lights, for the driver doesn't brake, the GPS slows down the motor.....
Oh, and government always knows where you are
.
I see a hard time for the thing getting approved over here.