I've got the GROM-IPD3 in my '04 Volvo S60R. I added the bluetooth addition and use A2DP to stream audio. Alternatively you could use the 3.5mm jack, it has an adapter for it. I also use it to charge the phone. The GROM-USB is more for iphone users, as it will allow you to view the song text on th radio. They claim this doesn't work in Android yet, but will be enabled soon via Bluetooth with our devices since they're AVRCP 1.4+. The bluetooth addition also comes with a microphone so you can place calls over it as well. Works pretty well honestly.
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