Volvo Meltdown at McDonalds

[Electronic M]

Looks like the firewall did its job.

Some cars use wire insulation that rodents like to eat, then the cars either catch fire or become inoperable.
If your injector seals leak or oil leaks onto the exhaust that can cause a fire too.

Regardless of the age of your car having an extinguisher isn't a bad idea.... Except for EVs/hybrids... Lithium batteries provide their own oxygen source so they can't really be extinguished...drive a burning EV into a lake and it'll keep burning underwater!