The argument goes both ways. Being able to customize Android means that it might have very different looks and versions between automakers, which would complicate things for app developers.
I don't think cars should integrate closely enough with either that it particularly matters which you use. Cars last a lot longer than phones. If the car you bought in 2003 integrated with a Palm and the one in 2007 with Blackberry both would be pretty useless today.
All you really need is integration of your maps/directions and music. Having it capable of going hands free and enable voice texting is OK for now, but both will probably be banned in most states before long since drivers in a hands free call are very nearly as distracted as those holding the phone - it isn't the driving with one hand that causes problems (many of us do that even when not holding anything) but the conversation itself.
The automakers ought to get together and create an open standard that they support and let Android and Apple write to that API. One wonders what a Fandroid or an Apple fanboy would do if their brand of choice made a deal with the "other guys". Would they buy a different car, switch their phone, or do without the integration?
There might not be as much a battle between Android and iOS in automobile sector as its currently seen in smartphones. Are there enough applications that are needed in car that can be supported by these OSs.
This is quite interesting. I suspect android has a big advantage here since the car manufacturers can make their own version, just like many cell phone providers have done. Apple, being a closed system will have a much harder entry. They would basically need to create a new product that is intended to be the car computer. I can't even really imagine them doing that.
Even if they have a good sense of what' s needed in terms of software for infotainment systems, it'll be interesting to see how long OEMs can stave off the likes of Apple and Google. This is a fascinating market and one with a great deal of opportunity to be had. I would be surprised if more hardware companies aren't preparing offerings for CES 2015 and beyond.