That's your C-pillar trim completely messed up. It's peeling and can't be "tucked in." Usually people just replace that piece. Before fingers are pointed, are you sure it wasn't like that before?
'02 ///M5 Imola Red / Imola Red '09 335i Alpine White / Coral Red
'04 E55 AMG Brilliant Silver / Anthracite
'96 318i Alpine White / Black
'01 330Ci Titanium Silver / Coral Red
'96 328i Jet Black / Black