Well I got it installed tonight, took a little while because I took my time and wanted it done cleanly. Everything worked out, new chip from GROM works great, GROM works fine with the Drive + Play and all in all I'm pretty happy.
I bought a pro clip low mount from pro clip to mount the controller on, and I mounted the screen on the plastic piece above the head unit, right above the felt piece.
I tied it into the cig lighter, and it worked fine.
Heres the mount I bought, price was a little ridiculous, but I'm happy with its location, while driving it works great, my arm is resting on hand brake and I can scroll through songs effortlessly.
ProClip Mounting System - Choose Your Country
Here I snapped a few quick pics, excuse the blurriness, my camera is garbage and I rushed it haha...
It would be awesome if the Drive + Play itself was black, so it would match a little better, and if the lights were amber, I thought about tearing it apart to see if I could change the LED's, but it won't be in my car too long, hopefully being replaced with a Nav sometime. I just set the back light timer to 10 seconds so it dims and you can't see the bright blue.
All in all I spent around $30 for the brand new Drive + Play on ebay (there are tons of them cheap), $30 for the mount, and the $80 for the GROM (which I got way before the D + P). A little steep in my mind, but its a nice setup and I'm happy with it.