obviously this isnt a financially optimum option, but I have always tried to locate another stock rim and tire for my vehicle(not a spare steel or donut, but a regular rim and tire like whats on the vehicle), and use that as my spare. If its a truck or SUV, and it hangs beneath the car, I usually dont have to modify anything ab it fits just as easily as the original steel or donut spare, but on some of the sedans I have had to remove or modify the styrofoam insert in the trunk to get it to fit. Anyways, I prefer this route because it allows me to have a straight up permament replacements for a flat tire instead of a temporary one, and it also allows me to rotate it in with the other tires whenever i rotate them every 3,000 miles. that way i can ensure my spare is always in good usuable condition and it helps slow down wear on the rest of my tires by cycling in a fifth one every rotation. Now obviously if you have tires that cant be rotated side to side because they are unidirectional, this wont work. I just like it because then i dont have to change my tire back from a steel or donut to the original, i can just leave it and then after getting the other tire fixed, it becomes the new spare. Plus, they all wear evenly, instead of having 3 worn tires and the spare with a brand new tread. So i would love it if the OEM's included an extra identical 5th wheel instead of a donut or steel spare. But thats just me. like i said at the top its probably not a financially viable option. us the extra weight would be a detrime t to fuel economy.