Drac
I think they do, as I have recently been in one which is not only 'black-boxed' but also has cameras front, rear and inside the cab. There is some debate about whether these are allowed to be active, particularly re patient confidentiality, so no one has actually confirmed whether they are in use or not !
There was a previous thread on this and the instructions are that there is no 'driver discretion' regarding use of lights and sirens. They MUST be used at all times when the vehicle is enroute to an emergency ie. enroute to a patient or going to hospital. This was apparently a joint services decision after the Newcastle case which Drac referred to above.
I've just finished a 12 hour shift and I can tell you my head is bloody well ringing 😡