MIG gurgled happily, sounding much like they
were saying:

Yup, an ambulance service fast response vehicle, staffed by a
paramedic. The vehicle they send so as to get expert medical help to an
incident faster than a full-fat ambulance may be able to get there.

Although probably not in the Yorkshire colours (may have been less
garish).

Unlikely.
Green battenburg's fairly standard for ambulance service nationally.