Maxi-Cosi recommends to travel rearward facing as long as possible. Parents are advised to use the (rearfacing) infant carrier until the top of the babies ears extend past the top of the seat back. There are some combination seats (e.g. MiloFix) that allow rearward facing up to 13KG, and because their internal dimensions are bigger they allow longer rearward facing travel than an infant carrier.
The biggest leap of safety benefits is achieved by travelling rearfacing up to the age of at least 15 months. Maxi-Cosi recommends to extend this period even longer, preferably up around 4 years old. The 2wayPearl is developed recently to allow rearward facing up to 105 cm (approx. 4 years old) in combination with the 2wayFix base.
Future new product developments of Maxi-Cosi will also allow rearward facing travel for toddlers.