If speeding is illegal then why don't cars have a speed limiter?

Good question...

I suspect it will come in, eventually. Cruise-control will have that effect but only if you engage it within the speed-limit!

My "sat-nav", a TomTom unit, displays my speed and the speed-limit for the road I am on, excepting for temporary restrictions presumably; and the indication changes to red if I stray over the limit.

I think heavy goods vehicles already have speed-limiters.

Because Americans demand the freedom to break the laws?

They do it's called the driver

Then, what's the purpose to follow traffic rules? Just ram everything on the road.

I do not want to work tonight