Sure, the regulatory regime needs to be relaxed to quickly bring on more manufacturing capacity. I believe it will be. Throwing it out entirely and allowing anybody to manufacture and sell medical devices from their garage is not going to happen.
That being said, auto manufacturers likely have no experience manufacturing these devices. The don't know which optimizations will be dangerous. They may not recognize they are doing anything different from an experienced manufacturer.
When quality breaks down, it will be important to have appropriate records to know which other devices are also defective so that they can be replaced, repaired, or used with appropriate caution. If manufacturing is still ongoing, corrective action in the manufacturing plant will be needed. GxP regulations require this type of record keeping for very good reason.
An experienced manufacturer will be needed to get manufacturing going and to supervise it to ensure it has an acceptable level of quality. Even if the experienced medical device manufacturer has legal indemnity, failures of the temporary factory could stain its reputation. I find it unlikely that any reputable medical device manufacturer would want to take on supervision of an inexperienced workforce in an unproven facility without the force of the regulation they are accustomed to as a means to force behavior that they know leads to predictable outcomes. Surely, experienced members of a quality organization and the FDA will figure out how to right-size some of the practices called for by regulation.