> If people are afraid of releasing the car's code, the agency doing the emission testing could make it a bit less obvious when the car is being tested. That would make it harder to cheat.

I'd say requiring the release of all source code involved in or connected to control circuitry in the car (i.e. anything other than in-vehicle dash systems that are completely isolated from CAN, etc.) would be reasonable. The safety concerns outweigh any proprietary benefit to the companies involved.

It would also create a lot of pressure for the manufacturers to actually isolate the non-critical value-add parts from the critical keep-the-car-driving parts, which would increase security.

Exactly.

I made some ignorant comments about the legitimacy of how much pollution is actually caused by these cars considering "tailpipe" emissions tests are a thing where the test is segregated from the car's computer system entirely, and we haven't heard much about these types of tests failing.

The real question I have is, if the vehicles are actually producing less emissions during the test, how come they can't use the same method to produce less emissions during normal operation? If the "defeat device" had some adverse effects on the car's operation, which I imagine it does, I would also think that it would be apparent when running the test. "Sounds like this car is running on 2 cylinders at 75 RPM..."

Edit: I'm just going to wait for the videos, someone will eventually detail what's going on.