For the first quarter of 2007, Toyota sold 2.35 million cars, more than any other auto maker in the world. U.S. company General Motors had held the title of world's top auto seller since 1931, not counting two brief periods in the 1970s and 1980s when labor troubles led to production problems. GM sold 2.26 million cars worldwide in the first quarter of this year. While Toyota's sales have been growing around the world, China is the only place where GM has seen recent growth. Rising gasoline costs have helped Toyota sell their more fuel-efficient cars, but some Americans claim that Japan's protected economy, which makes it difficult to sell US cars in Japan, has given Toyota an unfair advantage.