Connection Issue - Workaround
I have this same exact issue with my Motorala Backflip (connect/disconnect loop) running Android 2.1 and my 2011 Hyundai Sonata. I have tried many different things posted on many sites. Here is a variation of one solution that works for me to connect consistently.
1. Delete the pairing in both the phone and the car kit.
2. Pair the devices.
3. Allow continued access to the phonebook when the prompt appears in the phone's notification bar.
4. Leave bluetooth on.
5. Turn off the car.
Now whenever you get into the car, do the following:
1. Start the car.
2. Immediately make a call from the phone (I call my voicemail).
3. After you hear the call switch from the phone to to the car kit, hang up the call using steering wheel controls.
What I think is happening here is that by making a call during the connection process, you a forcing communication through the entire bluetooth stack. This must not be happening during the automatic connection process (but should be).
Try this and see if it works for you.