[koruptor]

I have another version of the GROM (Model USB3 for trunk). I like it a lot. It took a while to wire everything up and I had to take apart all the carpeting and paneling in the trunk to install it. It was installed as a "CD changer". I fed a female USB cable through the center console so it's accessible via the center storage area (where the nav computer is). It came with a microphone but I chose to to use it since I have one built-in my steering column already.

I've worked with GROM customer support before and they're awesome. I bought mine with the DSP adapter but realized I didn't need it. I was able to send the adapter back and they refunded me for that portion. No questions asked.

The version of the GROM I have allows for BT connectivity (A2DP), and has USB input. You can play music via USB but it only trickle charges your phone (no fast-charge due to low energy output). I have tested audio via iPhone (lightning) and Android phones (micro-USB). Audio works just fine. On very rare occasions BT doesn't sync up when I turn on my car, but I just fall back on USB.

This model can play music via flash drives.

Yes, my steering wheel and stereo controls can skip tracks in either BT or USB mode.

Interesting side-note:

You can pair your phone to both the GROM and your built-in BT for the car. However, on iPhones you cannot set which connection is for phone calls and which is for audio (i.e. music). It's all or nothing in this situation.

Android users rejoice! You can actually set the BT connection to feed phone calls to your car (if you have the built-in BT module and mic), while simultaneously outputting music audio to the GROM unit.