The McLaren formula one team apparently takes a 3D printer with them to the trackside during races.
This is supposed to allow the creation of replacement parts during the race (although I’m not sure about how the F1 rules people regard that).
Today’s invention is inspired by that idea, but for a much more prosaic purpose.
In order to extend the life of everyone’s car tyres, imagine a small 3D printer that fits inside a car’s wheel arch and delivers a very fine layer of rubber onto the surface of a tyre, in the correct tread pattern.
A car, parked on say a Quickjack, might have four of these operating, perhaps every night, scrubbing and rotating each wheel whilst providing a nice, new, vulcanised rubber surface by morning.