Antenna on wire only w/ Radio Not CD

On my Prius, there is no amp remote wire from the head unit available.  There is an antenna on but it's only active when the radio is in use, not the CD.

My questions are:

1. How common is it for a head unit's antenna on only to be hot when the radio is on but not the CD?

2.  Even assuming one didn't have a need to use that wire for an amp remote turn on, don't most people prefer a power antenna stay up anytime audio is on, whether it be CD or radio?   I know I like to switch back and forth and I don't want the antenna going up and down every time I do, even though it's not doing anything for CD sound and may impede the aerodynamics of the car.

1) Always.  That's how it works.

2) I understand your point, but see 1)

1.  Yes, most cars are like this, but not all.  The new Jaguars keep the power antennas powered up when listening to CD.

2.  I agree.

actually most of my customers prefer not to have the antenna up when they are playing discs.... sometimes it's just a cosmetic thing, but often - especially with front fender mount antennas - the antenna will "sing"  at highway speeds, which can be annoying..... i had a customer a month or so ago that made us take out a brand new unit he had put in because the power ant circuit and the amp remote circuit were both active anytime the unit was on and he hated that.... his old Alpine had a tuner activated ant on circuit and that's what he wanted again....  the fact that his antenna was up while he listened to discs seemed to drive him nuts...

different strokes for different folks....