I had the same problem.. here was my solution..
Just put Alpine's new CDE-HD137BT head unit in my car, and when the D4 bluetooth isn't being cranky it works great for navigation and listening to things like YouTube channels in the car. The radio is designed to let you control Pandora on an Android phone, but I can't get that feature to work with my Droid4 (unrooted). The phone is paired & connected to the head unit, BT audio is working, I have the Pandora app running with the "automotive mode" setting activated in the app, but the head unit just says "NO PANDORA". Seems this is a permissions thing -- I had to grant a pop-up permission question to let the head unit download my phonebook, but nothing pops up for Pandora. This would seem like an Alpine forum question, but they don't have one. Ugh. Figured I'd ask here to see if anyone has suggestions.
Alpine's tech support was great. They walked me through my issue in getting the Android HTC Evo 3D (Android v. 4.0.3) to pair via Bluetooth with my Alpine Alpine CDE-HD149BT head unit so I could use Pandora mode.
I had read elsewhere that the Pandora via USB was meant only for iPhones.
Androids will always stream Pandora to the head unit via Bluetooth, and NOT through USB.
Alpine confirmed this was true.
Alpine had me check to make sure I was using the latest version of the Pandora app for Android (which was 4.2).
The crucial parts were the following four things-
1. ON THE PHONE, IN THE PANDORA APP SETTINGS, under "Advanced," the "Bluetooth for Automotive" must be selected.
2. ON THE HEAD UNIT, hold down the "audio" button so that you get into the settings. the different settings there are, for example.. general, display, tuner, IPOD&USB, Application, etc.
Select "Application," then "Alpine APP," and change the setting from "USB" to "BT". Then, exit those menus.
3. ON THE PHONE, go into "Settings," then "Bluetooth" (where the list of your Bluetooth devices is).
Click settings for the "Alpine CD Receiver" (which looks like a gear or an equalizer next to the name). Make sure "Media Audio" is selected (both "Media Audio" AND "Phone Audio" if you also want to be able to take calls).
4. ON YOUR CAR, take the key out of the ignition and put it back in to allow the car stereo to completely reboot.
Make sure the head unit is set to Pandora mode.
Make sure the phone's bluetooth pairs with the car stereo head unit.
Start the Pandora App. The head unit should indicate that it is connecting and a few moments later, you should be streaming Pandora!