The window frame, I guess. Cars definitely still have frames, it's just integrated with the body rather than the old-fashioned ladder frames et al.

What I meant was that there's no real recess in the A pillars or front of roof for the glass to go "in" to anymore. The edge of the glass gets covered by trim or whatever so you can't see it, unlike the old days (so like 1990s down) where things used gasket.