I can't believe I'm the only one with this issue.  Just bought a Pioneer NEX4100 and I've had my LG for about a month.  Its running the latest version of Lollipop.  I keep getting incompatible USB.  I have tried multiple USB cables (Including the one it came with), I've tried with AA in developer mode.  THis is without a doubt one of the MOST frustrating things i have dealt with.  Between this and the hoops I had to jump through to get my wife's DA120 to work with Android I'm almost done with Pioneer.

Important Info:

4100NEX firmware rev. 1.08 

Android Auto ver. 1.2.084954 (2166577-release)

Google Play services ver. 7.8.99 (2134222-440)

LG G4 firmware ver. 5.1 (VS98611A)

I am rooted but nothing else done to the phone.

Can someone please help?  I only bought this radio for the SPECIFIC purpose to use my G4 on it with Android.  Without AA its just a expensive Double DIN radio.  Nothing else.  Thanks in advanced guys

Figure out whats probably my issue.  I bought a 4100 and they sent me 4000.  Took it to the shop that had my car (doing other work and they said they'd throw it in for free).  Its not the right HU.  Contacted Amazon and initiated a refund.  Bought the right model and paid for one day shipping.  Need ot wrap this up.