After market headunit question

[JC229]

Hey all, soon I'll be getting a VY Berlina or Calais (funds permitting) and have plans for an aftermarket headunit. I've noticed that under the instrument cluster on the dash it shows the radio station on the lcd screen, my question is what happens to this feature if the original h/u is disconnected? Does it disappear or does it get stuck forever on what it was on last? I'm not too concerned about having it work with the new h/u, just curious...

[one_and_only2004]

it just stops working ie your speedo will no longer tell you what you're listening to