Chariots in the Book of Mormon
These are the only passages that mention “chariots.” There is no evidence that they were widely used among Book of Mormon peoples. Indeed, the chariots mentioned in Alma 18:9-12 and Alma 20:6 were owned by a Lamanite king and were probably unique to royalty at the time. Wheeled toys have been found, along with paved roads, suggesting some sort of conveyance. At least one Aztec codex shows a ruler being pulled on a type of sled, with no wheels, which may be what was intended in the Book of Mormon.
For more information, including photos of ancient wheeled toys, see:
Paul R. Cheesman, “The Wheel in Ancient America,” BYU Studies 9/2 (Winter 1969)