It's a pretty simple fix. In the old days, governments had departments which would inspect cars, verify they complied with legislation, and even examine build

It's a pretty simple fix. In the old days, governments had departments which would inspect cars, verify they complied with legislation, and even examine build quality. Quite easy, when everything was basically physical. Now the ECU and modules are a black box, unknowable to such entities. Things can be caught (see VW scamming fuel/emissions tests), but it's by luck. So solution? We pass laws that all code, every bit of it, all chip schematics too, all firmwares are open source. Note I said open source, which in the old days just meant "readable". We're not talking GPL, all copyright would remain. On top of that, all build scripts and methods to flash modules / etc would be provided to governement test environments. Now we can test. Now, we can look for crappy code, hacky junk, fake emission cheats, bugs and more. Don't like it? You don't sell cars. Tough. The entire supply chain would be required to fall inline. It's really not that hard. In terms of security, that's what signing updates is for. And (for example) you can already take hobby tools, such as forscan (for fords) amd flash updates to modules. As long as it is signed.