Foaming Hubcaps are equipped with a device that enables a harmless type of coloured foam to be released on demand.

The generation of a sufficiently large volume will mean that a slowly driven vehicle will appear to be gliding quietly along on a bed of coloured bubbles.
-- xenzag, Jul 11 2017

I can see the utility of this, but perhaps you should explain for the others.
-- MaxwellBuchanan, Jul 11 2017


Only for the select few. Technicians and engineers are standing by.
-- xenzag, Jul 11 2017


Maybe for those M577 APC's, re-fitted for fire fighting ram raids.
-- wjt, Jul 16 2017



random, halfbakery