Hey fellow Subaru/music lovers,
If you've ever used Apple Airplay around your house to wirelessly control music from your iPod/iPhone/iPad then you know how useful this feature can be. I wanted to have this functionality in my WRX so I modified an Airport Express to run off the car battery. Check out below for step by step instructions. It's pretty easy if you're semi handy with electronics. The mod will work with any car, as long as there is a 3.5mm audio input port.
What's cool about having Airplay in your car is that all of your travel companions can wirelessly play music without having to go through any annoying and tedious bluetooth pairing, or passing around an auxiliary cable. However, note that Airplay is only useful if you're using iOS devices.
The Airport Express is being powered via USB. The AE audio output is being fed into the center console's 3.5mm auxiliary jack.
I set up the AE as "Dan's WRX". Now whoever is in my car can easily stream their music!
Step by step:
Gotta buy an Airport Express. The 2nd gen will work, but the 3rd gen boots up way faster. I went with the latest (3rd) gen.
Here's the AE opened up. The bottom pops off somewhat easily when using a screwdriver to pry from the corners.
Here's all of the boards removed from the AE, which are very easy to remove.
With the power supply board removed from the AE, it can be supplied with any 3.3V DC power supply.
I made a custom voltage converter from spare electronic boards that I had handy. My custom board, we'll call it the Green Board, accepts a male USB cable and converts the USB 5VDC into 3.3VDC using a DC-DC converter/regulator (LDO). There are tons of these on the market and it would be very easy to find one for cheap. In fact, you could buy a 12V-3.3V DC converter that could plug into your car cigarette lighter if needed.
I took Green Board and superglued it to the AE. I removed the female wall plug in the AE, which left a nice hole for the USB cable to fit through.
Here's the finished AE, with the case put back on and the hole enlarged so that it can fit a USB cable.