There's a difference between having the phone open and laying on the seat next to you, and chatting on it while the officers are talking to you. I could care less if you have your phone on the seat ... but, if you start giving info as to your location, the number and disposition of the officers, etc., then you're going to be removed from the car and separated from the phone. Likewise, if you are chatting on the phone while I am dealing with you, you are going to get asked to hang up or might even be separated from the phone.
Record all you want so long as you aren't putting me at risk or causing a distraction.