Hi I've just upgraded from an iphone 4 to an iphone 5s and now the new phone wont sync with my van's audio system for answering calls etc like my iphone 4 did up until I swapped it. I've a fairly new Renault kangoo and a work collegue tried his phone and that is fine. My phone is set to discoverable and I've updated the phone's software and turned it completely off and back on any idea's what I'm missing would be appreciated thanks.