I don't think that's needed. One of the manufacturers needs to get with the times and make an open platform and an app store and developers will come.
Once one of the cars starts getting useful excellent third party software that can say, do parallel parking or smart cruise control or some other killer feature (maybe a car "doctor" that guesses what's wrong with a vehicle at actionable levels), the other manufacturers will eat shit for a while with their own in-house clones and fail then finally give in and adopt the open standard.
They're better staying out of the software game entirely.