One of the best features of our phones is the options it gives us for music on the go. 16gb of storage, streaming from Pandora, Slacker, iheartradio and others. I've spent the last 3 months finding the best, most affordable way, and I think I've got it now. My priorities were functionality, ease of use and cost. I want to share what I've learned. You can do all this with an OEM or aftermarket stereo. Simplicity When you listen to the radio or a CD in your car, it's as simple as getting in and going. It plays where it left off. I wanted to stay as close to that level of effort as possible. If I have to get in the car, plug in the charger, plug in the audio, set up volume, start an app and select a song, I'm going to get lazy and stop doing it. For example, I tried this Bluetooth adapter. It was dirt cheap, but my Droid wouldn't automatically connect to it. I had to enable Bluetooth, open the settings, go to Bluetooth settings, choose the device, then go start my music. For my 15 minute drive to work, it didn't make sense. Cost There are a number of solutions out there, but many cost over $100. A simple Bluetooth receiver for my Pioneer stereo costs $180. Trying to balance the cost with everything I wanted was really the toughest part. Without my cheapskate mentality I would have spent 5x as much money and been done with it. What I didn't use, and why The MOTOROKR T505 looked, at first glance, like it did everything I wanted. It's a Bluetooth receiver and RF transmitter with hands free capability. The problem is, wireless RF transmitters generally suck. It's a low power analog signal that reduces sound quality. And hands free just doesn't really interest me. I also decided pretty early in my planning that I didn't want to use the 3.5mm audio jack on the phone. I have a Seidio car dock that I can slide the phone in to easily with one hand to charge it, and reaching over to plug in an additional cord was just one extra step I wanted to avoid. I hoped to be able to pull the audio from the USB port, like many phones are able to do, but with the Droid it's just not possible. So I needed to use Bluetooth. Also, as I mentioned above, I didn't use the Pioneer Bluetooth adapter for my aftermarket stereo. The $180 price was just ridiculous. The parts I ended settling on the Blackberry Bluetooth Gateway for $35ish. It uses the A2DP protocol, so it's compatible with any phone that can stream to wireless headphones or speakers, and it has a 3.5mm output. If you have an aftermarket stereo with auxiliary input, that's all you'll need. If you have an OEM stereo, you'll probably need an RF transmitter. I realize I said they are worthless -- but what you really want is a wired RF transmitter, such as this. This works the same as a wireless transmitter - you set it and your car stereo to the same frequency, but it is wired in line with your antenna and doesn't rely on weak radio waves to transmit the sound. Simply put, the quality is better. Installing it is simple enough - all you need to do is pull your stereo out, plug the RF transmitter in to your stereo and your antenna in to the RF transmitter. The caveats The biggest gotcha with my setup is that the Blackberry Bluetooth Gateway uses a USB charger (not included) for power. This means 1) you'll need to buy one and 2) you'll need to have 2 cigarette lighters in your car to power both the gateway and your Droid charger. In my case, I have an old power adapter that I've torn apart and wired directly to the harness for my stereo. My main reason was to keep everything as hidden as possible, but it has the added benefit of not using up my lighter ports. The pictures Ok, I don't have any yet. I'm working on building a new mount for my car dock and while I'm in the dash, I'll take pictures to document what I'm doing. Hopefully someone will find this useful. It was an unnecessary pain in my butt to figure all this out, so if I can save people from that, I'll be happy. Let me know if you have questions.