The wheels on my car were part of a £700 pack that included the wheels, grey mirrors and something else so trivial I still don't know what it is. Dealer told me but jiggered if I can remember, or care.
I actually think 17'' is the sweet spot for Leon alloys. 16'' is too wallowy and 18'' is too crashy. Wouldn't mind if the bigger wheels offered more feedback but they don't.
I quite like the ride currently on the 18’s plus I think they fill the arches which is a good look!
coming from a 1.9tdi Ibiza on coilovers... anything is less crashy though haha