Hey gang.  New 4000nex user.  Hopefully I can explain what I'm trying to convey....

Using Lg G2 with slimport connector and ARUR, everything is working fine.  I can load pandora from my touchscreen (phone screen on HU) and load pandora.  But if I want to use the built in pandora ap on the 4000 via bluetooth, its greyed out.  The only way to get that to work is to set the smart phone setting to bluetooth instead of hdmi.  This doens't seem right, as sometimes I might want to jump in my car and hit the pandora button for music without having to hook up the hdmi everytime.  Nor does it seem right that I need to change the smartphone settings, wait for reset, etc, every time I want to swtich between the two.

What am I missing?   Thanks

You are missing nothing, that is just the way the head unit works. unfortunately.

I'll go with Bluetooth. Using Pandora via HDMI will eat up your phone battery. Well, according to my Note Edge. I have mine plug to a Samsung HML adapter and play pandora via HDMI and my battery drop from 100% to 45% in an hour. Bluetooth will keep your phone charge while streaming Pandora.