The development of sustainable structural materials offering lightweighting potential addressing the environmental challenges of reducing CO2 emissions in the automotive industry, is needed. Fibre-reinforced polymer composites (FRPs) are light cost-effective materials giving directional strength, stiffness, durability and corrosion resistance. FRP candidate materials are semi-crystalline engineering polymers, e.g. polyamides (PA) combined with long glass fibres (PA-GF). Here, we will look at the structure morphology development in FRP materials using combined in-situ thermal and small and wide-angle X-ray scattering. This will allow us to follow the polymers crystalline structure development during cooling at temperatures mimicking industrial processing conditions, giving a unique insight into how processing affects the polymer morphology, mechanical and physical properties of the composite.