Word Scramble - Deities

In part it was a tribute to Matsuda Jujiro, the President of the company when it was renamed in 1931, but also as a tribute to Ahura Mazda, the god of harmony, intelligence and wisdom in Zoroastrianism. Mazda used to have a website explaining the origins of the name:

Key members of Toyo Kogyo interpreted Mazda as a symbol of the beginning of the East and the West civilization, but also a symbol of the automotive civilization and culture. Striving to make a contribution to the world peace and to be a light in the automotive industry, Toyo Kogyo was renamed Mazda Motor Corporation. “Mazda” was also a perfect way to pay respect to the substantial founder, whose family name is pronounced very close to “Mazda”.

As for the Nissan Qashqai, apparently Nissan chose it because it expected owners of that vehicle to be nomads too. I wouldn't know any of this if it were not for your question and Wikipedia--thanks for the education.

Especially since that's nowhere near the most common name for the deity in Japanese. It was 100% from videogames, not Japanese folklore.