Given how many people use iPhones, can't see why they are still pushing the rSap standard. Any phone that supports it basically becomes useless as soon as it is active as you lose the data connection on the phone.
That means no emails on the move, whatsapp, nothing apart from SMS and phonecalls. It is pretty pants in my opinion. I've got it in my Scirocco and used to use it when I had a Nokia phone. Was constantly switching bluetooth off and on to disconnect it from the car so I could download emails, very annoying actually.