Yes, that would be my solution. To be fair, I dont know if it would work. As I understand it, and probably wrong. A tracker is fitted and that logs the vehicle position every 5 mins or so and uploaded to the hardware company. The frequency of the uploads, i dont know.
The drive smart phone app will use its software to monitor driving style, harsh braking acceleration etc. probably report back to the software company. Motability will get the data if the parameters they have set, are outwith their limits. If they are monitoring voice, which I doubt, they will have a problem picking up anything over the sound level of my music.
Its nothing new, your smartphone monitors everything you do anyway. Even you have a clamshell old nokia or whatever your friends and families pick up your voice as well.
Your car reports all your driving parameters back to the manufacturer as well.