When I was thinking about a nexus 7, that docking thing sounded like the perfect solution. now that I've went with the galaxy tab, I'm having trouble figuring out how to make it removable, but still give it power.
I hate to see you abandon it. I've been through the same sentiment though, but all in all, android is simply way better than any software the current headunit makers have. I don't see what's keeping Sony, Pioneer, etc... from simply making an Android based head unit. For fear of using it while driving they can still include the parking brake function to enable certain apps, but of course we could still bypass it.