+12 Volt power from the Fuse panel or Relay plate... ?

I wired a USB port in my 1997 A4 from the wire that supplies power to the cigarette lighter. I crimped spade connectors on the wires but have yet to install the port on my dash. The power is always on with that connection, so no need to have the ignition turned on to plug in a cord and charge. I would like to keep my dash looking as stock as possible and am having a hard time deciding on a location. I might remove two of the unused plastic blanks and make a small panel there.

There is switched power available (ignition on only) at posts on the bottom of the relay panel. I used one of these to install an aftermarket cruise control. Use a volt meter to find the correct posts. There were one or two unused posts that were available on my B5.