AirPlay car stereos: where are they?

I have to admit that i'm not the most patient of people and generally want something before it is available, but AirPlay has been around for almost a year now, and yet there very few systems on the market, and none for car stereo.

In my opinion Airplay should be a perfect fit for car stereo systems, bypassing all those stupid cables needed to connect your iPod/iPhone, and with no need to have a docking station attached. All i would have to do then would be choose the car stereo system as the AirPlay device and Bob's your uncle. I want that, and i want it now!

For a short time it looked like one solution would be the Photofast AP1000 but that seems to have fizzled out as well.

So what is holding the audio industry back from delivering Airplay systems for car stereo; is it a matter of cost and licensing with Apple? or is it a driving security issue (which i can't see any arguments for)? Pershaps if anyone in the industry is reading this they could share some insight with the rest of us, that are un-patiently waiting for wireless audio streaming in the car to arrive.