We calculate bremsstrahlung spectra for intermediate energy heavy ion collisions to see the sensitivity of photon cross sections to reaction dynamics. Modeling the collisions with the intranuclear cascade, we find a clear collective quadrupole bremsstrahlung signal only for heavier nuclei, A>40. Maximum sensitivity to dynamics is likely for photons in the range of 10--30 MeV. For higher energy photons or lighter nuclei, there is a large background coming from the incoherent dipole component of the bremsstrahlung.