The Merc solution
Apparently the new Merc S-Class has "driver assistance functions", and, like the Tesla, monitors whether you've actually got your hands on the wheel, BUT the difference with the Merc is that it takes action when it detects you haven't done anything for a while.
This includes stopping the car, unlocking it and calling its emergency number, all on the assumption that you've probably died, because as you're driving an S-Class you're clearly a heart attack risk.
Not sure whether it actually pulls over or just stops you in your current lane (no doubt the fast one). The latter would then become exciting very quickly...