CAFE might be overcomplicated, but it isn't like GW Bush or others in his party (or members of Congress from Michigan of either party) were proposing alternativ

CAFE might be overcomplicated, but it isn't like GW Bush or others in his party (or members of Congress from Michigan of either party) were proposing alternative laws like you suggest. Their goal was and to weaken whatever efficiency requirements there are, full stop. Even the Biden administration has taken a pretty gentle regulatory hand with the auto and fossil fuel industries considering their own goals on climate change, for presumably electoral reasons.