Making In-Line Controller For Android

[Liam Brown]

Hi, i'll give you a bit of back ground first to give the problem some context.

I'm installing a Nexus 7 (2012) in my car dash board, at the moment I've moved my head unit to my glovebox and run it though the AUX straight from the table into that. I'm now looking at completely replacing my car head unit as I've seen a way to allow an android device to receive offline radio, but i don't want to loose my stalk controls on my steering wheel. My current "best"/only idea on how to control it with them is to intercept the stalk controls and use them to control an in-line adaptor (i'm thinking of replacing the buttons with transistors or similar) which will be able to skip songs, play/pause and volume which leads me to my questions.
Do you think this is possible?
I've read a few things on android devices not being able to be controlled by in-line controls.
Has anyone tried anything like this before? / Have any experience with editing a current inline control unit?

I'm open to any other ideas of how to do this as well, but i'd like it to not use Bluetooth as that will be occupied by my OBD device.
Thanks in advance!