Even if modern car failures are independent, forcing car companies to give the consumer an out after many consecutive failures of a component is not necessarily

Even if modern car failures are independent, forcing car companies to give the consumer an out after many consecutive failures of a component is not necessarily a bad thing. It would basically turn in to a Pigovian n^3 tax on reliability. But I suspect that you're overstating; a drive unit may well be truly independent, but something like water leaking in to the cabin wouldn't be. Even if 80% of components have independent failure modes, the remaining 20% will account for the vast majority of your lemon law invocations.