Why is my Bluetooth only redialing the last number?

I have bluetooth enabled car head unit, which works well with my Nokia 930 phone. However, the call out, it will only redial the last number. I wondered is it possible to change the settings on the phone so when it gets the last number redial command, it instead brings up Cortana in listening mode so i can instead say who I what to call?

Hi, I have same problem, would like to be able to start Cortana in voice mode when the Car sends the re-dial command. Would make the phone much more useful as the voice recognition in Cortana is the best I've seen and always gets right what I said. But is this possible?