Curently the EMPEG has a allways on lead that can be used as a remote for either a amp or to control the antena power booster suplied with the EMPEG, or if you like can also be used to triger the power antena. But as this is a always on lead (only on when the empeg is on though), the antena will extand even in MP3 mode.

As to the trafic / news service via the RDS system, any system should be able to pick these up with the power booster, even if the arial is down, so as soon as news signal is recieved, it could still be triggered. I reciently tested somthing simalar to this, my friends ALPINE system had no power booster but with a audio quality of about 4 out of ten with the arial down, it was still able to pickup and recieve the news signal and extend the areial to give a 10 out of 10 audio quality.