While we're at it, why not forcibly enforce some other strict laws?
Lets make it so your car doesnt start exactly on the day the tax runs out (easily done on most modern cars via the same "GPS tracking device" proposed) or maybe the day the MOT runs out (or maybe give them a weeks grace period to get it MOT'd), could also do the same for insurance.
Why not make every driver give a blood sample before the car will start to ensure their blood alcohol limit is < the legal max?
All of these things are easily installed into the majority of existing cars...
Why SHOULDNT we do this, and why shouldn't we enforce speed limits? For exactly the same reason smoking should never have been banned and things like fox hunting should never have been made illegal. I hate smoking, I dont agree with fox hunting but what I hate more than those things is the law being forced upon me, a government/general ruling system taking away my ability to break the law.
If I break the law, I should be punished and theres a very good chance I will be punished, but automatically enforcing the law leads to a general hatred of the system, as seen with speed cameras and a general divide between the people enforcing and the people being enforced. In the most radical of situations it can lead to revolution.
Technically speaking, no one should ever break the law and drive over 70, but to stop people doing so (and follow the example through in your head before judging it to be OTT) is paramount to the ideals of extreme fascism or communism. One person, through the systems of government or otherwise, should never be given the ability to control many others.
If I go 80 down the motorway, that is my choice to do so. I know its breaking the law and I know the consequences if I do so. I would rather resources had to be expended to catch me than I never have that choice in the first place.