  For a positive integer $n$, with $n \geq 4$, let $R_{n}$ be a free (nilpotent
of class 2)-by-abelian and abelian-by-(nilpotent of class 2) Lie algebra of
rank $n$. We show that the subgroup of Aut$(R_{n})$ generated by the tame
automorphisms and a countably infinite set of explicitly given automorphisms of
$R_{n}$ is dense in Aut$(R_{n})$ with respect to the formal power series
topology.
