Xfinity racing series is an American stock car racing series organized by NASCAR. Forthe 2017 racing season, NASCAR introduced new regulations for this series in order todecrease aerodynamic influence on vehicle performance. Using only open-sourceComputational Fluid Dynamics (CFD) tools this work describes the differences in theaerodynamic performance between the 2016 and 2017 TOYOTA Camry Xfinity racecars. During the CFD validation process, it was observed that none of the standardturbulence models, with default turbulence model closure coefficients, were able toprovide the race-car aerodynamic characteristics prediction with an acceptable accuracyas compared to experiments, and that a slight modification to closure coefficient valueswas required. This work demonstrates that it is possible to generate CFD predictionswhich are highly correlated with the experiential measurements by modifying theturbulence model closure coefficients, and it is possible to tune the standard k-ω SSTturbulence model. This work presents the differences between the flow fields around apre- and post-2017 race-car models using the high fidelity CFD simulations wasobtained.