Hi all I have done a bot of digging about trying to work out how to link my double din keyword head unit to my steering wheel controls in my gtvi.

Not too much coming to light on the search engines.

Has anybody been able to do this? If so and you please shed some light on it.

You need a Pac Swi to translate the signal.
Read through this:
http://www.pac-audio.com/swi/pdf/swi-jack_instructions-1.pdf

I've installed a handful of these and its a very easy install. Usually just a signal wire and the power to the unit then program. Make sure when you program the interface you press the buttons firmly but quickly without holding them down. Otherwise a press will jump many volume or skip many tracks

Mike

Mike, would pressing and holding the "next" button not translate it to fast forward?

Depends on the HU