Can you clarify the spare wheel carrier, ie. have you taken the spare wheel out of the car. Is it the thing that looks like the local blacksmith made it or are you talking about the cobra with the high level brake light on it. If so the cobra doesn't hold the spare wheel in place , rather its cosmetic to hold the high level brake light and as Dave has said, it's screwed to the ash frame with wood screws by a very competent technician!
