Are there any car holsters for the iPhone 4 like the one that came with my first Android phone?
I'm not familiar with the Android dock you refer to (was it for the G1?), but the dock I personally use is a Belkin TuneBase:



As you can see, it can hold an iPhone landscape (though it will also pivot into the vertical position), powers/charges the phone, connects to your stereo either through a 3.5" headphone cable or an FM transmitter, and has a button that acts like the in-wire headphone button on the Apple iPhone headphones so I can play/pause music, go forward and back, and answer calls without needing to touch the device.

My only complaints are that the dock connector is only used for charging the device (I have to plug in my headphone jack manually) and that the audio quality on the other end of a speakerphone call isn't that great.