Comment by ubernostrum

First: you literally do not know what you're talking about here. There's no Commerce Clause issue, because California's waivers to continue developing stricter standards, and the option for other states to adopt those standards instead of the federal ones, do not present a Commerce Clause issue: Congress has explicitly enacted into federal statute the permission for all of this.

Second: you still don't know what you're talking about, because even if there weren't federal statute explicitly covering this, California's rules apply to cars sold in California. SCOTUS has never reliably pushed far enough into expansive Commerce Clause jurisprudence to be able to strike that sort of thing down, and never ever will (hint: because doing so would create a legal precedent for federal gun control to pre-empt more-permissive state-level gun laws, something the Court's conservatives will never allow a hint of a possibility of a thought of an option of a shadow of a consideration of...).

Third: cherry-picking Commerce Clause cases is a really bad way to make an argument. SCOTUS has been all over the damn place on the Commerce Clause at different points in US history, and you can ultimately find a Commerce Clause case to justify basically anything you want to say, which is why any given example tends to be pretty meaningless as an argument.