Just to add to this thread. I did this for free myself on my car just following this YouTube guide and software linked in the vid description. It did cross my mind this could a virus ridden disaster that would brick my car, but I was feeling brave!
https://www.youtube.com/watch?v=Xuq9jjUqaWAThe video guide says you need OBDEleven, but I did it without, the software notes do say it just works and it did. I just did the software update with an SD card, it took about 15 mins all-in. Works a treat, have fully working Android Auto. Ive not tried Car Play as I don't have an iPhone.