I have a question about an irreducible representation of the (full) group $C^*$-algebra of an infinite dihedral group $D_\infty$, denoted by $C^*(D_\infty)$.

Ultimately, I'm interested in finding a primitive ideal space of $C^*(D_\infty)$ which is the kernel of irreducible representation of $C^*(D_\infty)$.  

But I'm having a hard time finding it.  

$C^*(D_\infty)$ is isomorphic to $A$, the universal $C^*$-algebra generated by two projections, $p,q$.  

So say $\pi$ is a representation of $A$ on some Hilbert space, $H$.  

Then $\pi(p)$ and $\pi(q)$ are projections on $H$.

So using this fact, should I consider an irreducible representation on $A$ first?

Or should I find pure states on $C^*(D_\infty)$ first since they correspond to irreducible representations of $C^*(D_\infty)$?  

I'm fairly new to this stuff, so any reference will be definitely appreciated.

And thank you in advance.