On the first msg, they say you order the one for x3 and fit it into the z4 dash. Thats why it looks different. Assuming the x3 and z4 has similar dash with the navigation unit/hole (from the chat).
If you have factory nav, I would suggest ordering from Avin assuming those return policy are still valid. You do not want to ship this back to china if they send the wrong unit, it was decently hard to communicate with them. Or if you have an Asian friend that can write back in Chinese, then you are golden
A few people had ask me for the dimensions of the template I was given for non factory gps unit, here are the screen shot measurements.. let me know if you guys need more info on this or additional measurement.
http://pmc-trust.co.uk/nathan/template01.jpg
http://pmc-trust.co.uk/nathan/template02.jpg
http://pmc-trust.co.uk/nathan/template03.jpg
http://pmc-trust.co.uk/nathan/template04.jpg
http://pmc-trust.co.uk/nathan/template05.jpg
http://pmc-trust.co.uk/nathan/template06.jpg
http://pmc-trust.co.uk/nathan/template10.jpg