Upgrade factory head unit.

[hutcheon21]

Hi,

I have a 2011 b8 Audi A4 Avant Black Edition, and I'm wanting to add sat nav to the interface. Any idea how? I've found a few things on eBay etc, but ideally I'm wanting to add android auto if I can. Is this possible? I keep seeing Android Auto head units online, but ideally I'd like to add this to the screen already fitted? If not, what's the easiest way to add nav? 

https://www.ebay.co.uk/itm/Audi-SatNav-GPS-Satellite-Navigation-Navi-Interface-Kit-Bluetooth-A4-A5-Q5-B8-/252428860362?clk_rvr_id=1518058266527&utm_medium=cpc&utm_source=twenga&utm_campaign=twenga&utm_param=eyJlcyI6MCwicyI6OTcyMDIzNywiY2kiOiIwMzY2YzY1OTBjY2M0MTVkNzc1YWRlY2MyZmEzMDE4NiIsImkiOiIyNTI0Mjg4NjAzNjIiLCJ0cyI6MTUyNTI4MzE4OCwidiI6Mywic28iOjE1MDAsImMiOjE0OTh9&rmvSB=true

I've seen this, and the xcarlink, but I'm thinking if I purchase the xcarlink then I won't be able to use the DAB radio whilst using the xcarlink interface.