I think Xiaomi Roidmi 2 is the better version of it... Aside of the car battery thingy it has a mic build in to have a (nearly) hands-free phone and the smartphones audio is transferred into a radio signal using that Bluetooth-connection...
I think Xiaomi Roidmi 2 is the better version of it... Aside of the car battery thingy it has a mic build in to have…