I've just been through this myself, was tough to pick especially as certain bad things heard about non mainstream aftermarket. Would have love to go down the route of a Pioneer Android Auto unit - but by the time I had got all the cables it was going to be £550+. Ended up getting a Android 4.4 HU (Chinese aftermarket) despite the horror stories. Got it from a UK seller (iceboxauto) to give myself a bit more comeback and installed it last week. I'm still working through some of the teething issues, but I am very happy with it and iceboxauto have been really quick to answer my questions and send me one additional cable. I went for their A6964 unit but there are other ones which look more OEM. Was a quick install and am using Nokia HERE for mapping (free), bluetooth works etc. After I installed it I did more of a search and found out some other favorable feedback on the same unit!