None of the above was a must for me (heated seats desired though ) which proves that spec is very much dowp to personal wants or needs
I would add sport seats to the top of your list for multiple reasons & this was a main criteria for me
Aside it was more important to find one well cared for , properly serviced & at the right price
Idrive was not on our list when we were looking at all and ours doesnt have it. Dont think I miss it either as I dont really use satnav.
M Sport spec and everything else on your list is enough for us.
The aluminium carbon trim was also what we wanted but this has now been wrapped with carbon vinyl.
Wind Deflector a must if you like roof down cruising over 60mph
i-drive for sure, sat nav is a good system
Extended bluetooth for the usb mp3 player port in the arm rest
I've just had an MSPORT gear stick and steering wheel fitted, so much nicer than the shiny leather standard jobbie.
I've not used cruise control or heated steering wheel yet, and I find park-assist annoying but I guess it all adds to the resale value 8)
Heated leather sports seats, wind deflector and rear parking sensors. But really a personal thing and as Mr Wilks says getting one with a good SH and a tidy body and interior should be your first priority.
I suppose for 're-sale the more spec the better.