I'm having trouble getting a harness to make the steering wheel controls work, as it's touch and go as to which one will actually work. As for the display, not a chance. I've only seen Kenwood HU's be able to make the display work, and you need a £100 adapter
It says on Car Audio Direct, you need this specifically for the Vauxhall Car
http://www.caraudiodirect.co.uk/29609-s ... -3482.html
and this for the Pioneer
http://www.caraudiodirect.co.uk/incarte ... -3489.html