I bought this unit of ebay and recieved it today. I hooked it up in my car and I can confirm it works very well on android (tested on my galaxy note phone, and galaxy tab 10.1) This unit is recognized as a normal keyboard.
The thing you have to do, is to first map the buttons with the included windows software, so you have to connect it to your windows pc first. It has 4 different channels, so a lot if different buttons should be possible (one channel can be used for reverse cam). I havent tested it out very much yet, but with the combination of keyboard shortcuts and Tasker, i think this could give endless possibilities
Only issue so far is that I either have to connect the steering wheel control unit, or a charger. Does anyone know about a usb hub that will both charge the tablet and provide a usb port for the steering wheel control?
if i'm reading you correctly, you're having the same problem as many others - there's no cable that provides OTG (USB host) and simultaneous charging for the Galaxy Tab. info for making your own OTG & charge cable here: http://forum.xda-developers.com/show....php?t=1155065