Legacy Addition: Unpermitted Structure, Is now a good time to resolve?

[Benson Davis]

I own a rental property that has an unpermitted family room that was added before I purchased it in 1995. Our current tenant is moving in August. We are planning to upgrade the kitchen, bathroom and a bedroom. If I call for an inspection on the new upgrades, I am concerned the inspector will see the unpermitted structure and require us to it tear down or upgrade it. Should I try to fix permit the structure?  What is the likelihood an inspector would notice it? I am also concerned about overdue property taxes, as the addition was not documented by the county.

Thoughts?