First generation advanced high strength steels (AHSS), as lightweighting materials, have been widely used in the current vehicles due to their high strength properties with relatively good ductility. The introduction and availability of the third generation AHSS have offered greater opportunities for automotive engineers to use those steels in many additional structural components requiring both higher formability and higher strength to meet the more stringent government standards on crash safety and fuel economy. The excellent formability of the 3rd generation AHSS allow design engineers to design more complex forming processes for springback control and more complex part geometry for higher stiffness. On the other hand, computer simulations have been extensively used to conduct feasibility study for manufacturability of new materials and to validate vehicle crash performances. Accurate material characterizations focused on the requirements in numerical simulations are extremely important since the material decision, manufacturing and component/vehicle performance validations are often made in early vehicle development stages, specifically for AHSS including 3rd generation AHSS due to their complex microstructures containing multi-phases. In this presentation, the material properties and advantages of 3rd generation steels are reviewed and compared with conventional dual phase steels. The material characterization processes for key material properties required in the material cards for forming and crash simulations are provided for U. S. Steel 3rd generation steels (XG3TM). The validation processes for the calibrated material cards through experiments and industrial applications are also discussed and presented. The advantages of higher strain hardening rate of 3rd generation steels are highlighted and validated in the forming simulations for the industrial parts. In addition, the different kinematic hardening and fracture behaviors of XG3TM steels are also discussed from the material modeling prospects. The challenge areas in material modeling and simulations are discussed, including the lack of advanced material models or numerical simulation technologies in more accurate prediction of springback, press tonnage, edge cracking, and fracture initiation and propagation.