I still carry the 2nd version of the OEM spare (BFG series 1 were all recalled for early sidewall cracking), mounted on a 14 x 6" spun-magnesium racing wheel and a non-propane gas inflater bottle with the required fill hose & valve. I normally wouldn't use a spun wheel on a street car, but the spare tire's 50 mph/50 mile distance limits are so low, I think it will work- if required. This spare easily sits in the front trunk with a tie-down stud & wing nut, covered by a trimmed '80s Buick felt cover that matches our trunk felt. I mount the spare upside down & use the backside wheel cavity as a tray to carry small spare parts, a qt of brake fluid, spare lug nuts & the inflater bottle. Wipe rags keep things from rattling.
Over the years, I've TIG'ed & redrilled an '80s Porsche 16" aluminum spare wheel/space-saver tire to fit a Pantera, & also converted an '80s Thunderbird 18" x 4" high-pressure spare to fit. This last aluminum wheel barely fits inflated, in the front trunk & needs 3 of the 4 mounting holes TIG-welded & redrilled to Ford 5x 4-1/2" bolt pattern, then an adapter ring shrunk in to resize the big register hole from 4-bolt T-bird to 5-bolt Pantera size. The Porsche spare was quite a bit heavier than stock but the other two choices turned out lighter than stock. With some imagination & work, there are other choices. If you have to leave a disabled car alone out in our desert boonies, drunken cowboys sometimes come by & shoot up abandoned cars.....