DPMJET is a Monte Carlo model for sampling of hadron-hadron, hadron-nucleus, nucleus-nucleus and neutrino-nucleus interactions at accelerator and Cosmic Ray energies according to the two-component Dual Parton Model. Here we describe new features in version DPMJET-II.5: Implementation of new DPM diagrams for an improved description of baryon stopping in nuclear collisions and improvements in the calculation of Glauber cross sections. The new diagrams allow two quite different extrapolations of the model to the highest Cosmic Ray energies. The new version of the model is compared to experimental data on hadron-hadron, hadron-nucleus and nucleus-nucleus collisions.