After not getting anywhere with the 0x3F5 ID although it is related (sends display information to the Head Unit - there had to be some other related ID that switched the head unit.

Thanks to the work done by BiggRanger I was able to use the time ID 0x3E6 as a reference to refine the point at which I activated a phone call and could look back from the 0x3F5 "Connect" string a few seconds.

The amount of data on the bus is quiet a lot even when the ignition is just in the accessory position and nothing being activated there is around 200 messages a second.