Hi Trevor have never seen a 3.6 with Cruise Control I would have thought the car would need to be Automatic to start with,
The V12’s all had it but initially it was proven to be lethal. I was coming off a motor way in the early days 1986/7 and it would not cut out when I hit the brakes quite hair raising & frightening, Jaguar all but called me a liar and said it was not possible. Just a few months later there was a re-call after someone had been killed.
There is nothing in the parts book re parts for 3.6 cruise control.
Pleased to see you are still with us Trevor from around 2011.