The biggest issue is that there isn't a power point in the glove box. My Prius and Mazda both had/have power outlets where their aux/ipod jacks were located.
This thing is great for ipods in that scenario:
http://www.amazon.com/Belkin-F8V7058...6067253&sr=8-7
It looks like just a charger, but on the bulb of the 12V plug it has a line out from the dock connector.
Having a line out instead of going through the headphone jack is nice because it bypasses the volume circuitry, giving you cleaner sound and consistent volume levels. The output from the dock is consistent, no matter what the volume level on the ipod is.
So with that Belkin thing, you get in the car, connect the dock connector, and you immediately have power and clean sound with predictable volume.
With the way the Smart is set up now, I'll probably have to make another 12V location behind the dash or else run the headphone-jack line out from the Belkin gizmo (plugged into the existing 12V outlet) behind the dash and into the glove box. Then I'd just stash the ipod in the cup holder for easy manipulation, seeing as I'll be giving up the steering wheel track controls I have in the Mazda (sniff).
-Drew