It’s easy to see that 輪 contains a car (車). The right-hand side of 輪 means “to align neatly.” The bottom part, 冊, represents a bundle of bamboo tablets, bound together. This character now serves as the counter for books. For example, 二冊 (nisatsu) means “two books” or “two volumes.” In 輪, the 人 and 一 atop 冊 represent a lid capping off the bundle of tablets. (Do they really need a lid?) The right-hand side of 輪 also acts phonetically to mean “to roll.” The aligned, rolling parts of a vehicle are wheels, which is the original meaning of 輪.
