Now here is the simplest solution and well on the way. Just replace the worn-out parts and keep the old heap on the road indefinitely. As transplant techniques are perfected and refined, the age-old dream of immortality is now within the grasp of mankind. There simply aren't enough parts to go around. You need the job lot once a year to save 20 percent, folks.
Big executives use a heart a month just as regular as clockwork.
Warlords, paying off their soldiers in livers and kidneys and genitals, depopulate whole areas. The poor are rising in mobs. They are attacking government warehouses where the precious parts are stored. Everyone who can afford it has dogs and guards to protect himself from roving bands of parts hunters, like the dreaded Wild Doctors, who operate on each other after the battle, cutting the warm quivering parts from the dead and dying. People have lost all shame.