  We aim to study the presence of both rotation and expansion in post-AGB
nebulae, in particular around IW Car, a binary post-AGB star that was suspected
to be surrounded by a Keplerian disk. We obtained high-quality ALMA
observations of 12CO and 13CO J=3-2 lines in IW Car. The maps were analyzed by
means of a simplified model of CO emission, based on those used for similar
objects. Our observations clearly show the presence of gas components in
rotation, in an equatorial disk, and expansion, which shows an hourglass-like
structure with a symmetry axis perpendicular to the rotation plane and is
probably formed of material extracted from the disk. Our modeling can reproduce
the observations and shows moderate uncertainties. The rotation velocity
corresponds to a central stellar mass of approximately 1 Mo. We also derive the
total mass of the molecule-rich nebula, found to be of ~ 4 10e-3 Mo; the
outflow is approximately eight times less massive than the disk. From the
kinematical age of the outflow and the mass values derived for both components,
we infer a (future) lifetime of the disk of approximately 5000--10000 yr.
