I bought one which cost under 200, ran full Android (a slightly older one, to be fair), and I was able to self-install with no real issues. Just unplug old stereo, and plug in all the same things into the new one. I have a 2013 Golf.

Mind you - it's a little janky after 5 years, but an awesome value for what it cost. I know what you're thinking: Yes it has Netflix and Retroarch. No, I don't ever use those.