Tennessee law does not require that you "announce." However, if you have a firearm/firearms visible about your person, it probably would be wise to do so. If it's a routine traffic stop (i.e., you know
you were speeding) and no weapons are exposed, I don't see any reason to draw even more unwanted attention to those out of state tags.
It took a Carter to bring us a Reagan
"The principal feature of American liberalism is sanctimoniousness. By loudly denouncing all bad things — war and hunger and date rape — liberals testify to their own terrific goodness. More important, they promote themselves to membership in a self-selecting elite of those who care deeply about such things.... It's a kind of natural aristocracy, and the wonderful thing about this aristocracy is that you don't have to be brave, smart, strong or even lucky to join it, you just have to be liberal."
-- P.J. O'Rourke (1992)