Yes, sometimes 'car' and 'cdr' are replaced with 'first' and 'rest' and are some of the first things you cover when learning the language, so I don't think the names would really be hindering adoption for those that try to learn the language. The benefits of car and cdr are that they can be composed: (caadr l) instead of (car (car (cdr l))) for example.

Well, if you use "first" and "rest", then (caadr l) could become (firrest l) or something like that...

I like Racket's second, third, fourth,... etc. [1]

I don't think there's an equivalent to cddadr for example, but at that level of deconstruction you're better off abstracting the data structure (maybe a struct [2]) or using some other mechanism like match [3]

[1] http://docs.racket-lang.org/reference/pairs.html?q=second#%2...

[2] http://docs.racket-lang.org/reference/define-struct.html?q=s...

[3] http://docs.racket-lang.org/reference/match.html?q=match#%28...

Yes but can you do caaaaaar or caaddaar or cdaar, etc. with head and tail?

In 5 characters with cadar you can express walking along a tree structure to get exactly the node you want.

car, cdr, cadr, and friends are discouraged in some Lisp communities where pattern matchers are available.

Sure. caaaaaar -> heaaaaaad. cadar -> heaiad. It's one more character, but if you really want to express yourself that way, there's no reason you couldn't...