The automakers are not complying with the disputed California laws because they are not valid. They are not valid because California lacks jurisdiction to make these laws since they involve interstate commerce. The different levels of government have different areas of responsibility. For goods that are traded globally it is not efficient for local governments to be involved in setting standards. This is one of the main advantages of international trade agreements, removing from local governments the setting of local standards and instead promoting global standards which results in better products at lower cost.
If California wants to reduce global warming they can raise the state gasoline tax, encourge people to walk to work by increasing housing density and with mixed-use development of housing and work, and providing better mass transit.
