English and Japanese pronunciations never line up well which complicates communications, so people tweak spelling all the time. Toyota or Mazda or muRata is all about that. Matsuda was always matsuda in Japanese but spelling it as Mazda skips whole ordeal about matt-sudah or mar-TSOO-dah. Mazda is just short and close enough. Isuzu unfortunately has the yee-zoo-zoo problem, it's more like "iszh" but it won't roll on any tongue and there isn't much that they can do about it now.
"main farm", "rich farm", "pine farm", "bell tree", "sun field", "river cape", "fifty bells", it's all just surnames. Nothing particularly more awe inspiring than any regular surnames would be.
Toyota's founder is Kiichiro Toyoda (with a 'd'), and the company was originally named Toyoda, named after the founder. It was later changed to Toyota because it looked better in Katakana script (8 brush strokes, which is a lucky number), and it had a better meaning in Japanese. Apparently Toyoda is a farmer's name, and the company did not want to be associated with farming.
Similarly, Mazda comes from it's founder's name Matsuda, but was changed to Mazda when the first wheeled vehicles were produced (Mazda-Go). The official claim from Mazda is that it was named after Ahura Mazda, a God, but it is widely speculated that the name change was done to make it more appealing for international markets. I don't speak Japanese, but I have seen several videos on social media where the Japanese still pronounce Mazda as Matsuda.