You are right.The sanctions imposed upon India are to blame as well.While India was virtually writhing under sanctions and trade related bans almost everywhere across the World,the Japanese industries in general and automobile sector in particular received massive boost.they were welcome everywhere.
another significant boost came in form of the 1970s fuel crisis that had affected mainly W.Germany,US,Canada.The US made cars were notoriously fuel hungry,while the Japanese cars made by Honda were fuel efficient,although less powerful,but exactly what a typical middle-class American family needed.the stricter emission control rules in US also aided since the Japanese cars had lower emission.The Japanese cars started selling like hot cakes and gained market monopoly.