Successful integration of an antenna onto a vehicle platform poses many challenges. Vehicle features impact antenna performance by blocking, reflecting or re-radiating energy, and co-site interference can impair the effectiveness of multi-antenna configurations. Platform motion and environmental factors such as terrain and buildings may reduce system effectiveness in actual operational conditions. Furthermore, radiation hazards may pose risks to nearby personnel. Modeling and simulation provides a powerful tool to aid in understanding these issues and developing solutions. This paper provides a variety of examples of simulation-based assessments used to analyze antenna performance, identify problems, and evaluate potential solutions.