The early cars, at least the first 3 and first batch of 100, had the slide hold-down from San Jose spot welded to the trunk floor. This was removed by SA and re-located for the spare hold-down under the rear shelf. I don't remember exactly when, but Ford changed to the hook style setup, sometime around March IIRC. SA couldn't use these, so they left those in place and were able to acquire the slide brackets from Ford to continue with that configuration for the rear shelf spare.