TITLE: Automorphisms of virtually abelian groups
QUESTION [5 upvotes]: Let $G$ be a finitely generated virtually abelian group (i.e., $G$ contains $\mathbb{Z}^n$  with finite index for some $n\ge 2$). Is there anything known about the outer automorphism group $Out(G)$? 
For example, is $Out(G)$ finitely presented? Is it linear? Is it residually finite?

REPLY [2 votes]: The OP has since proved a vast generalization of residual finiteness in the virtually abelian case: the outer automorphism group of a virtually compact special group is residually finite.
Antolín, Yago; Minasyan, Ashot; Sisto, Alessandro, Commensurating endomorphisms of acylindrically hyperbolic groups and applications, Groups Geom. Dyn. 10, No. 4, 1149-1210 (2016). ZBL1395.20027.