  Heavy-ion collisions at low beam energies explore the high density regime of
strongly-interacting matter. The dynamical evolution of these collisions can be
successfully described by hadronic transport approaches. In March 2019, the
HADES collaboration has taken data for AgAg collisions at $E_{\rm Kin}=1.58A$
GeV and in this work, we provide predictions for particle production and
spectra within the Simulating Many Accelerated Strongly-interacting Hadrons
(SMASH) approach. The multiplicities and spectra of strange and non-strange
particles follow the expected trends as a function of system size. In
particular, in AuAu collisions, much higher yields of double-strange baryons
were observed experimentally than expected from a thermal model. Therefore, we
incorporate a previously suggested mechanism to produce $\Xi$ baryons via rare
decays of high mass $N^*$ resonances and predict the multiplicities. In
addition, we predict the invariant mass spectrum for dilepton emission and
explore the most important sources of dileptons above 1 GeV, that are expected
to indicate the temperature of the medium. Interestingly, the overall dilepton
emission is very similar to the one in AuAu collisions at $1.23 A$ GeV, a hint
that the smaller system at a higher energy behaves very similar to the larger
system at lower beam energy.
