You can turn it off or on when driving - when it is off you get the little warning symbol on the dash. By default it is always on when you start the car.
One of the 'attractons' of having an older car or something like a TVR where you don't have TC.
While it is no doubt a 'safety' feature that will benefit those who do not like to fully explore the car and/or their abilities, for those who do like the challenge and used correctly, having the TC off brings the car 'alive' and is in a ZED that is very rewarding in my experience.
Its there for a reason Colin - not many of our members have 40+ yrs driving and motorsport experience!