One critical thing: regularly check these donut spare tire pressures and adjust - I do it every few months (nice to have a good 110V inflator at home for this purpose)!
They generally need to be kept at 60+ psi (depending on make/manufacture).
Because, people, for some unknown reason(!), feel comfortable driving at highway speeds on these spares rather than the recommended 50mph or less!
And, if these spare tires are under-inflated (often the case!), they could easily overheat and blow apart. Then, the driver will be kinda dead when the car goes out of control.
Z