There is an indiegogo crowdfunded campaign for a device called AAWireless <INDIEGOGO id="aawireless">https://www.indiegogo.com/projects/aawireless#/</INDIEGOGO> which are designing a device/dongle which plugs in to your USB port and enables Android Auto Wireless if your phone supports it. Only other workaround is AAGateway where you will need to set up another device which your phone can connect to wirelessly in order for it to work. So I guess in time this will be possible as a retrofit. I have sent messages to VW requesting whether there are any purchaseable accesssories whcih could enable this, but unfortunately your car needs to have WIFI capability for the wireless android auto to work off the bat. So maybe VW Discover Media systems would work. Let me know if you happen to find anything else.
Thanks for reply Luke.... sounds bit tricky,dunno if its worth hassle...from what I read online I thought the lastest Android auto app updates would enable wireless connection ..that is if your cars system is compatible...anyway think I'll wait till they make it as easy as possible..👍