We have regulations that make cars take more damage in low speed impacts to make them safer for pedestrians, but pickup trucks with a hood line higher than an average adults head are legal.

In many countries in the EU, vehicles will flash either the brake lights or the signal lights when the ABS system activates to help warn the driver behind them. This has been proven to reduce the rate of multi vehicle accidents. That type of system is still illegal for car makers to use in the US.

Other countries had adaptive headlights that reduced glare for oncoming vehicles for years before the US finally allowed it.

The fact is, emissions regulations in many ways have nothing to do with health or clean air. I don't drive a diesel truck myself so its not like I'm trying to defend my own behavior or anything. I'm a former automotive engineer who is unfortunately very familiar with the regulations and how nonsensical they are.

If my car fails while I'm driving through the desert and leaves me stranded in 100+ degree heat in the summer, that would be a critical situation.

If my car fails while I'm driving on a busy part of I5, that could be a critical situation.

I get that the rolling coal mods or whatever aren't designed to improve reliability, but things like deleting EGR or modifying the control logic for the DEF system are and can prevent a vehicle from failing in a situation that could be life threatening. Again, the government already knows this which is why they order their vehicles with those exact modifications already done.

My car is a bit older but its perfectly reliable. It doesn't require a monthly subscription, it doesn't track my location, it doesn't have a remote kill switch, and the title isn't owned by some bank. It would even blow fine on an emissions test. I still couldn't use it in California though because some of the original emissions equipment has failed and original replacements are impossible to find so alternative replacements have had to be used instead.