  A rare coincidence of scales in standard particle physics is needed to
explain why $\Lambda$ or the negative pressure of cosmological dark energy (DE)
coincides with the positive pressure $P_0$ of random motion of dark matter (DM)
in bright galaxies. Recently Zlosnik et al. (2007) propose to modify the
Einsteinian curvature by adding a non-linear pressure from a medium flowing
with a four-velocity vector field $U^\mu$. We propose to check whether a smooth
extension of GR with a simple kinetic Lagrangian of $U^\mu$ can be constructed,
and whether the pressure can bend space-time sufficiently to replace the roles
of a $w=-1$ DE, $w=0$ Cold DM and heavy neutrinos in explaining anomalous
accelerations at all scales. As a specific proof of concept we find a
Vector-for-$\Lambda$ model (${\mathbf V\Lambda}$-model) and its variants. With
essentially {\it no free parameters}, these appear broadly consistent with the
solar system, gravitational potentials in dwarf spiral galaxies and the bullet
cluster of galaxies, early universe with inflation, structure formation and
BBN, and late acceleration with a 1:3 ratio of DM:DE.
