> (car #(fubAr quux)) => 'lambda
>
> would be *very* surprising to most users.  That kind of computation is
> what functions are for.

Taking the car of a function is not valid anyway.

Byte compile:

  (defvar myfunc (lambda ()))

Evaluate:

  (car myfunc)

Error:

  Debugger entered--Lisp error: (wrong-type-argument listp #[nil "\300\207"
[nil] 1])
    car(#[nil "\300\207" [nil] 1])
    eval((car (byte-compile (function (lambda nil)))) nil)
    eval-last-sexp-1(nil)
    eval-last-sexp(nil)
    call-interactively(eval-last-sexp nil nil)
    command-execute(eval-last-sexp)

Or in the *scratch* buffer:

  (setq lexical-binding t)
  (car (lambda ())) ; => 'closure