Update: I was finally able to talk to the previous owner (super cool guy) and he confirmed the following mods
BMW Performance -
springs/dampeners
Exhaust
carbon fiber spoiler
Carbon fiber interior trim
Kidney grill
Short shifter
Alcantara boots
Side skirts
///M front & rear control arms
///M front sway bar
50/35% tint
Hartge roof spoiler
Alufelgen cs7 18x8/9 matte black
Gloss black diffuser
Also told me the turbos were just replaced under warranty ~2k mi ago.
And offered to give me other parts he had taken off before it was traded in (carbon fiber diffuser and front strut bar) as well as parts he never got around to installing.
I told him I lived in WA state and he said he would ship the smaller stuff (no strut bar/diffuser
)