Interesting question. Partially it's that the global car market is huge so there's enough profit to go around even with a lot of companies. I think the more im

Interesting question. Partially it's that the global car market is huge so there's enough profit to go around even with a lot of companies. I think the more important reason is historical, though. The car companies of today were almost all established back in the days when shipping cars internationally was expensive, and operating a factory in a foreign country was difficult. So each major industrialised country wound up with a few manufacturers after a lot of consolidation -- in the US dozens of manufacturers got reduced down to three. Then there's three German, two French, one (major) Italian... Japan is a weird case but it is still consolidating... Only in the last few decades has the car market become really global, and as a result there's ongoing consolidation continuing, eg Fiat-Chrysler and Renault-Nissan.