The hot medium created by colliding two heavy ions is both expanding against the vacuum and very strongly self-interacting. This makes it a system which is trying against all odds to thermalize. The study of nuclear collisions at ultrarelativistic energies seems to be the quantification of non-equilibrium corrections to seemingly thermal observables. In this talk we focus on the late hadronic stage of the evolution of the fireball. More specifically, two recent developments on the physics of the afterburner, using the code SMASH. First the role of proton antiproton regeneration in the end yields , and second, the incidence of non-equilibrium physics in the anisotropy of direct photons.