The increasing demand for environmentally friendly materials, combined with stricter European regulations for the reduction of gas emissions, has prompted researchers and industries to find suitable alternatives to lightweight, high-performance synthetic materials. In this context, natural fibres composites (NFCs) play a pivotal role. Their high availability, low weight, low cost, and high strength and stiffness make them excellent candidates for environmentally friendly vehicles. Despite these advantages, they are high sensitive to environmental conditions, harvesting, and extraction processes, which make difficult predicting their mechanical behaviour. In this work, flax/epoxy composites subjected to low-velocity impact (LVI) tests are analyzed from experimental, analytical and numerical points of view. From the results comparison emerges that the analytical model can be considered a valid tool to provide a first good approximation of the load-displacement experimental trend. Despite this, a deeper level of detail is required; therefore, a finite element numerical model (FEM) is designed because of its ability to capture also the damage phenomenon. However, it is well known that a FEM model requires the use of parameters that cannot be experimentally determined. For this reason, an optimization procedure is considered. Since the aim of this study is to provide an overview of possible solutions for the partial or total replacement of synthetic fibres in the automotive sector, other types of tests need to be analyzed. In particular, the in-plane crashworthiness behaviour is investigated from an experimental and a numerical point of view to evaluate the crush energy absorption properties of two different geometries: flat and corrugated (S-shape). In this particular case, the results obtained with purely flax reinforcements are not good for our applications, therefore different hybrid solutions - obtained combining carbon and flax - are shown. The obtained results highlight the importance of hybridization as a possible solution for the design of tailored composites able to reduce the carbon footprint, without renouncing to the excellent mechanical properties that only synthetic fibres are actually able to guarantee. The idea of a total biocomposite is still far from our applications, but the investigation of flax fibres combined with different types of more sustainable matrices, i.e. bio-epoxy and thermoplastics, is one of our main challenges.