The design of car interiors can affect the angle at which a car seat fits – and therefore the angle at which the child rests within the seat. In designing every seat our goal is the optimal balance between safety and comfort. The steeper the angle of the back of the infant carrier, the greater the protection in the event of an accident. The flatter the baby is in the shell, the easier it is for a young child with developing neck muscles, but the safety systems of the seat may no longer be working at optimum capacity. Britax generally advise that consumers seek advice from qualified personnel when buying and fitting a child seat. If a qualified car seat fitter judges that the angle of the shell is too steep in conjunction with the vehicle seat, then for Britax seats you can request a free inclination adapter .This adapter is very easy to install using the supplied manual.