//M Strut Brace as standard?

[Mr Whippy]

For most companies, you now have to declare all factory fitted extras as well.

Would be kinda hard for the 2nd, 3rd, 4th.... owners to know what was factory fitted or not though :?

Exactly, you could get on to the insurance regulators who would throw the book at them.

Things like 'extended storage' a whole whopping net in the passenger footwell. Or a wind deflector, a bit of plastic between the headrests!?

If it really mattered to them, they could just check the VRM/VIN with BMW, get the spec list, and not cover things beyond that.

Insurers who care about such things, imho, are best avoided full stop. If they are looking for ways out of paying on optional extras then that is their mantra. Find excuses first, pay up later, if they can't get out of paying!