The bodykit is just a bodykit... any MINI could have one fitted; it is not indicative of model or specification. What year is the car?
In the case of first gen models, the bodykit is actually called the "Aero" kit, whereas on second gen cars, the comparable kit is indeed the "
JCW" bodykit (with the Aero kit being a much less popular "toned down" version). Also, without wanting to sound patronising, "
JCW" and "Works" are the same thing... you may well be aware of this, but part of your post sounded slightly unclear.
What info did you request from BMW? In terms of "registered" - my R53
JCW was (and still is) "registered" as a Cooper S with 170bhp when you look up the registration number, despite being a 210bhp
JCW. The Works tuning kit was installed by the dealer following delivery, and this information (in terms of non-factory R53s) will never be "registered" as far as I'm aware.
That said, any BMW/MINI dealer would (or certainly should) know if the tuning kit had been fitted, whether they carried out the work or it was done at another dealership. What exactly did they say when you spoke to them?
In terms of insurance, under the circumstances outlined above, it's up to you to TELL the insurance company that you have a Cooper S
JCW and not just a regular Cooper S.
Does the car have the
JCW exhaust? Badges on the front and rear? Can you take a picture of the engine bay to post? If I remember correctly, there should also be some form of certification with the handbook, assuming the previous owner hasn't lost it.
I'm not convinced that the car in question ISN'T a
JCW, but without proper clarification it would be foolish to assume either way based on the limited information.