Personally I have found it useful to keep in mind that it's the pair that's fundamental and not the list. IIRC it was pg that made the point somewhere that car and cdr are acceptable because there really aren't any slam-dunk general terms for the parts of a pair.
True, and if you're thinking of them as a pair, then "first" and "second" are appropriate. But if you're using them to implement a list, then "second" is misleading.