I have an Alpine head-unit in the Sierra and found out that they have a compatible Bluetooth module (the KBC-300/400 or something like that) that plugs in the back and activates the phone controls on the front.

Anyone used one of these? Good, bad, indifferent?

And any recommendations on best place to buy - prices seem to vary from about £80-£150

 

I've got one. It's handy to have but the other person gets echoing on their end