Bluetooth adapter for car stereo?

I have an alpine x305s which has the 30 pin ipod cable but I need something that will work with my iphone 5. I bought the 30pin to lightning adapter from Apple but it stopped working after a 2 months so I'm looking for something wireless.

I did some research and what I need is a 30 pin bluetooth adapter that work with digital inputs like my car stereo. The ones I looked at on Amazon and ebay only work with analog inputs.

Do you guys know where I can get one that works with my stereo? The alpine bluetooth module cost about $80 so I'm looking for cheaper options before I decide to buy that.

I use a dual stream Bluetooth adapter that plugs into the 3.5 audio port and allow the use of 2 Bluetooth headsets or speakers simultaneously from one device.

http://how-to-fix-earbuds.blogspot.com/2012/01/how-to-connect-two-bluetooth-headphones.html