Move over Parrot Asteroid, there are several android-based dual din car stereos shipping now from Asia.
1.The Easy Rising ES666 is available direct here for under $400 USD. This device features a fully removable android tablet which can operate all stereo functions and low profile hard controls for when the tablet is undocked. It has TV tuning, bluetooth, RDS, wifi, 3g, GPS, and DVD. The included tablet is a nice bonus prize.
2.If you paid too much for your car, you can snag a Dynavin. It looks like you can get the DVN-E46 for your BMW, but they don't make generic DIN units. This unit runs android 2.2.
3.Another Chinese manufacturer is trying to sell a pretty sleek model. However, I couldn't find anyone reselling this in the US yet, and a 1000 unit minimum order is too rich for my blood. That said, it is obtainable in bulk so it should be for sale somewhere.
If you don't mind buying from a no-name Chinese company, you can be one of the first to grab one of these bad boys. In contrast, the Parrot device is rumored to run a locked-down app store and an older version of android, and God knows when/if it is actually coming out. I find it odd that major manufacturers are not producing these types of units when the after market is threatened by Ford Sync and the upcoming GM Intellilink systems.