  Polar metals are an intriguing class of materials that simultaneously host
free carriers and polar structural distortions. Despite the name "polar metal,"
however, most well-studied polar metals are poor electrical conductors. Here,
we demonstrate the molecular beam epitaxial (MBE) growth of LaPtSb and LaAuGe,
two polar metal compounds whose electrical resistivity is an order of magnitude
lower than the well studied oxide polar metals. These materials belong to a
broad family of $ABC$ intermetallics adopting the stuffed wurtzite structure,
also known as hexagonal Heusler compounds. Scanning transmission electron
microscopy (STEM) reveals a polar structure with unidirectionally buckled $BC$
(PtSb, AuGe) planes. Magnetotransport measurements demonstrate good metallic
behavior with low residual resistivity ($\rho_{LaAuGe}=59.05$
$\mu\Omega\cdot$cm and $\rho_{LaAPtSb}=27.81$ $\mu\Omega\cdot$cm at 2K) and
high carrier density ($n_h\sim 10^{21}$ cm$^{-3}$). Photoemission spectroscopy
measurements confirm the band metallicity and are in quantitative agreement
with density functional theory (DFT) calculations. Through DFT-Chemical
Pressure and Crystal Orbital Hamilton Population analyses, the atomic packing
factor is found to support the polar buckling of the structure, though the
degree of direct interlayer $B-C$ bonding is limited by repulsion at the $A-C$
contacts. When combined with insulating hexagonal Heuslers, these materials
provide a new platform for fully epitaxial, multiferroic heterostructures.
