You get a flat, and under the carpet in the trunk is one of those “donut” (or “temporary”) spare tires – skinnier than the tires on your car, with a prominent warning about maximum speed on the side.

Flat tires are a major inconvenience and, since Murphy’s law applies to them too, tend to happen when you are in a hurry to get somewhere. In any case, whether it happens in your driveway or on the ...