Not to cast aspersions on anything, but I would like to ask if temporary/space saver spare tires are subject to rubber aging/ozone damage the same way regular tires are? If so, where does one by a new tire (the rubber part only) to replace the aged tires? Or am I overthinking this in some way? I know that the space saver/temporary tires don't see the UV exposure that regular tires do considering they are hidden away the vast majority of the time, but they still get some exposure to ground level ozone, considering that any factory original F/M/J body factory original temporary/space saver spare tire is now coming up to 40 years of age, it may be a consideration.
My J bodies (one Cordoba, one Mirada CMX) both have the regular sized spares. Those spares take up a lot of room in the trunk, and are also right in the middle of the trunk, right up front, just behind the passenger seats, at an angle. I would like to use that space for a sub woofer box, and would like to come up with a different solution. My initial thought was to get a temporary/space saver spare, and secure it into one of the "wells" that they J bodies have on either side of the trunk, along with the jack and jack handle/tire iron. If there are temporary spares available with the right bolt pattern, I think any temporary/space saver will do, even modern ones, as they are so skinny that offsets don't make much of a difference. The alternative to that is a bottle of tire "Goop" and a small air compressor, which may not be a solution depending on how damaged the regular tire is.