None of the cars have an auto dimming mirror - it was on the spec sheet but they've never even been an option. If you get leather seats, they will be heated - heating was standard on all leather and leather/alcantara seats.
I wouldn't bother with the satnav. The whole head unit is dated, to say the least; if you really want built-in nav then buy a decent aftermarket head unit with it built in.
Auto Vs manual: the auto is an old-school torque converter, I think they claimed it had the fastest torque converter shift in the world at launch, most other autos are DCT these days so if you're used to those it may feel slower to shift but by all accounts it's not too bad.
The manual can be difficult to get into 2nd when cold; most owners report some degree of difficulty. It can apparently be improved with a change to different oil in the box. I haven't had that done, but I do have an aftermarket shift spring and an insert for the gearbox mount. Those improve the 2nd gear a little, and give a very sweet gearchange (some complain about a slight increase in noise from the mount). Very cheap upgrades, and excellent value.