Well, close to Richardson my friend. It is a Carrollton address - located on the border between Carrollton and Addison. It is barely a block from the underground tunnel underneath Addison Airport (on the west side of the field). I'm also from Dallas (originally) and know the area well. It is indeed an upper class industrial area with much office space for small caps.
I haven't been by that specific address, but I have driven past that very spot hundreds of times. I still have family in Farmers Branch, Carrollton, Irving, Plano, etc.