3 months prior you get your pin etc so wont be able to order before then really so beginning of dec.
however i reckon a lot is going to change before march, hopefully some vehicles will come back on the scheme.
theres not a lot of choice in kuga size at the moment nothing i would call a bargain anyway.
personally i do start going to showrooms and doing homework at least 6 months before.
it can be a pain getting test drives and my pain limits the wandering i can do in showrooms although fortunately in chesterfield about 10 dealers are on one road which helps.
i think the popular alternative at the moment is to extend your current lease until something reappears that you like. you can extend for 2 years but at any time in that 2 years you can swap without penalty. its what i would do at the moment the way the chip situation is.