Amazon offers the Aukey Portable Wireless Bluetooth 3.0 Audio Music Streaming Receiver w/ 3.5 mm Stereo Output, Hands free Calling for Car Sound system (BR-C1, White) for $7.99 with free Prime shipping. That's the best price we've seen for any Bluetooth Aux port adapter and this one actually has a mic which is great for calls in cars or office speakerphone.

  • Portable Bluetooth solution for wired speakers, headphones, stereos, and sound systems.
  • Bluetooth 3.0 technology with A2DP support ensuring crystal clear sound and high quality stereo music
  • One button easy pairing, pairs to iPhone, iPad, iPod, Android smartphones, tablets, transmitters, computers in seconds.
  • Supports hands-free calling with built-in mic
  • Package content: Aukey BR-C1 Bluetooth receiver, 3.5mm Audio Cable, 3.5mm to RCA cable, USB charging cable, User manual, 18 Month worry-free warranty