monopoly....they can be gud in some cases...such as when a big firm/few big ones help to develop an industry with R & D, invest...bring in good technology, benefit from economies of scale...and so produce at a lower production cost.
HOWEVER...Toyota...Honda...Suzuki and all the others that maybe...have sworn to be unproductive and produce cars at the greatest cost per unit, also due to low regulation (this is being changed rapidly by the government) they have been able to establish very high prices as consumer demand is VERY VERY HIGH...even after high prices...Demand pull inflation!!!!!