As Radar REMPI has been used extensively as a diagnostic technique in gases, the question arises if it can achieve the same successes in plasma environments. In this paper, we investigate the effects of a 10 Torr air plasma on the Radar REMPI diagnostic. We also consider the effects of magnetized plasma by introducing an external magnetic field. Although for timescales shorter than one microsecond the background plasma has little to no effect on the signal, for timescales greater than one microsecond there is a substantial increase in the signal due to the perturbation in the plasma from the laser-generated plasma of Radar REMPI. We assess the magnetic field measurement capability of Radar REMPI in the presence of magnetized background plasma. We then show an additional magnetic field effect that can impact Radar REMPI signals in longer timescales due to magnetic field effects on the diffusion of the laserplasma.