The CAE-CAT Integration Demonstrator aims at fulfilling the increasing demand of automotive engineers to correlate data from simulation with data from physical test. The demonstrator shows how SIMDAT can help to overcome the current engineering problem that data resulting from simulation and test processes are stored in separate data management systems with heterogeneous data models and without common interfaces, which makes data correlation a tedious and error-prone task. The CAE-CAT integration demonstrator developed by the SIMDAT Automotive Activity partners AUDI AG, MSC.Software and ontoprise GmbH integrates this heterogeneous data from CAE and CAT via ontologies with SIMDAT Grid technologies ensuring secure communication. While SIMDAT Grid technologies ensure the seamless access of remote data sources the use of semantic technologies assures the seamless integration of heterogeneous data models. The demonstrator has successfully proven the value-add of the combination of the two technologies.