For a car, the reason why it works is because it has an axis that it is built on. If it doesn't have that, it won't work at all.
You see a car without an axis and it's your friend's car. He's all like "isn't this a cool car?" You reply: "Gee, cool" (じく) very sarcastically.
Currently there are no similar looking kanji which exist in the WaniKani learning system