See "probably much, much less" (since diagnostic systems have many false negatives, and only work on some subsystems) and my argument about wet conditions (which causes greater than 4% of accidents). Furthermore, the absolute number of accidents is not a sensible number to look at unless you're also totaling up the absolute number of drivers inconvenience. Both the absolute number of accidents and the absolute number of downsides (wasted time, driver frustration, unnecessary repairs) will be proportional to the number of cars, so you should divide out by the number of cars.
First, you are not engaging with any of the points in my reply. (Do you disagree that the fraction of accidents that diagnostic systems can plausibly stop is <<4%? We can't tell.)
Second, you keep suggesting that I made claims about this being "trivial" or "noteworthy". I did not. I made a claim about what would be a good system, not the notability of the absolute number of accidents stopped.
