That's because Apple Carplay wasn't really designed with a linear input method in mind. It should be list-based, not grid-based. Like old Nokia phones, which often only had up-down buttons paired with two action buttons—no left-right.

Give each menu item it's own tone and you could probably navigate it blind after a little bit of practice. Importantly, in this type of system, each menu list should be short—6-7 items max—so that it is easily navigable and memorizable.