Isn't there power available at the map lights? Likewise the sunroof (for cars with a sunroof of course). A little time with a meter will be very enlightening. I'll be doing mine whenever it gets here. I'll never be without my V1. I've never really seen the value of the remote display, so I don't bother with one.
I love Posi-Taps. Super simple and easy to pull out down the road: