  Let $N(5,D_5,X)$ be the number of quintic number fields whose Galois closure
has Galois group $D_5$ and whose discriminant is bounded by $X$. By a
conjecture of Malle, we expect that $N(5,D_5,X) \sim C X^{1/2}$ for some
constant $C$. The best known upper bound is $N(5,D_5,X)\ll X^{3/4 + \epsilon}$,
and we show this could be improved by counting points on a certain variety
defined by a norm equation; computer calculations give strong evidence that
this number is $\ll X^{2/3}$. Finally, we show how such norm equations can be
helpful by reinterpreting an earlier proof of Wong on upper bounds for $A_4$
quartic fields in terms of a similar norm equation.
