The APC can be produced early in the game by soviets. The APC Rush tactic involves carrying several rocket soldiers, grenadiers, or flame throwers in an APC and infiltrating the enemy base in the early game, in an attempt to destroy some buildings. Harming the economy in the early game by destroying Ore Refineries or Ore Trucks can be fatal to the opponent on the long term.
Sometimes, people use empty APCs for quick scouting, and their opponents mistake this for an APC rush and attempt to destroy the APC. This can also be done on purpose to confuse the opponent or keep them busy.