With difficulty, because I love it all, I pick the pano roof which can keep the interior cosy or airy, as you wish. Also the interior lighting, especially at night! But AMS1979, you didn't say what your favourite part was!
What is there not to like!
Ok but favorite parts...Pano roof, the perforated brake disks and red Mercedes calipers, the rear bumper on the AMG pack is hot! and the interior seats with the SLS air vents! red seatbelts!
If this car had a spare wheel, even that would be lovely!